Whenever I tell friends in the IT industry that I majored in biology, they are always shocked. Friends around me joke that I am a chef held back by code. Honestly, I am genuinely interested in cooking. Many friends who dislike cooking find this hard to understand. Part of it might be genetics, and part of it is sheer practice – my mom started teaching me to cook when I was 6, and by 13 I could host guests on my own. Despite being comfortable with frying, stir-frying, boiling, and deep-frying, after more than 20 years of cooking, I never became a real chef – at best, a chef among friends. My fundamentals are solid for both Chinese and Western cuisines. So why have I never moved beyond that?

A Sense of Achievement

Among my hobbies, cooking is just one. The reason I find it interesting is probably the sense of achievement and satisfaction it brings. During my school years, every summer I took over all the cooking at home. One time, I was about to stir-fry pickled chili peppers (one of Hunan people’s favorite dishes). Pickled chili is usually stir-fried plain without other ingredients. That day, walking along a path through the fields, I spotted fresh green soybeans by the roadside and had a sudden idea: “Red pickled chili paired with these green soybeans – that must taste amazing.” The visual contrast, plus the texture – pickled chili turns out dry and grainy, and the soft bite of green soybeans would complement it perfectly. So I shelled half a plate of green soybeans and stir-fried them with the pickled chili. That evening, my mom tasted my creation, praised it enthusiastically, and asked who taught me this dish. I said: “I invented it myself!”

Beyond cooking, guitar is another hobby. In college, to pass the time, I started teaching myself guitar from video tutorials in the dorm, practicing in front of the bathroom mirror until I could play a full song on beat. I never learned staff notation, but give me tablature and I could play along – from classical to folk to electric, I explored them all. The workflow was always: watch videos, find GTP scores, import into Guitar Pro, and practice on repeat. I even spent a few hundred yuan on a Guitar Pro License. One night in 2013, I recorded a few of my best-practiced songs. Every time I replay them, I get lost in the familiar melodies.

A Sense of Defeat

Many friends, upon learning I majored in biology, are curious: what made me choose IT instead? I originally chose biology because I was interested in it – actually, I was even more interested in medicine, but my family did not support studying medicine, so I settled for biology. After all, a biology graduate is almost half a doctor. Because of my interest, I did well in organic chemistry and biochemistry.

Once, in biochemistry class, during the chapter on DNA/RNA replication, the professor said: “DNA replication always proceeds from the 5’ end (the 5th carbon position of deoxyribose) to the 3’ end (the 3rd carbon position of deoxyribose).” I was immediately puzzled: why 5’ to 3’ and not 3’ to 5’? After class, I approached the professor with this question. She had probably never encountered a student asking something like this, looked a bit embarrassed, and told me this was an experimentally observed phenomenon – she did not know the why either.

DNA Replication

In another biochemistry class, the topic was gene expression (protein synthesis), and another conclusion was stated: polypeptide chain synthesis proceeds from the N-terminus to the C-terminus. I asked the same type of question – why does polypeptide synthesis go from N to C? The answer I got was the same: it was experimentally determined. These two questions haunted me throughout college.

In a biochemistry lab session, we practiced the PCR (Polymerase Chain Reaction) technique – in plain terms, DNA amplification, artificially copying DNA (for example, when doing DNA/RNA analysis from a tiny sample that is not enough for a single experiment, you first amplify the sample DNA/RNA to a sufficient quantity). PCR requires a critical primer (somewhat like a catalyst in traditional Chinese medicine) that activates the entire PCR process. This primer is itself a short nucleotide fragment, only a few dozen bases long – short and structurally simple. But at the time, this reagent could not be manufactured domestically (or the purity was insufficient, leading to high error rates). From that point on, I lost my enthusiasm for biology research. Looking back, if my questions had been properly answered, I might never have lost faith in biology.

The Best Teacher

Later, I started learning Web programming. At first, I was self-taught from videos and asked questions online, but I never grasped the essence – I could only copy other people’s code without knowing how to create my own. Until one day, a teacher surnamed Hu gave me a CHM file of “JavaScript: The Definitive Guide, 5th Edition.” That was when I discovered something called API References, and a whole new world opened up.

The saying goes: interest is the best teacher. But I found this is not quite true. Among hobbies driven by interest, some lead to modest achievements, some fizzle out, and some become lifelong careers. Why such vast differences? What ultimately determines how high we grow?

Take cooking. Is a qualified master chef someone who only excels at cooking techniques? I believe mastering technique can make you a head chef, but going from head chef to master requires knowledge far beyond cooking itself – nutrition, botany, zoology, microbiology, and more. Only by understanding the structure, texture, and processing of ingredients can you create new culinary techniques, rather than just following recipes by rote.

The answers to the two biochemistry questions that haunted me turned out to be surprisingly simple – energy cost.

The raw material for DNA synthesis is dNTP (deoxynucleoside triphosphate – the collective name for dATP, dTTP, dGTP, dCTP). The 5’ end carries a phosphate group. By releasing the beta and gamma phosphate groups, it provides the energy for DNA replication, and the remaining phosphate ester can bond with the 3’ hydroxyl group. Going in the reverse direction would require first breaking the 5’ phosphate group to bond with the 3’ hydroxyl – breaking the phosphate group consumes more energy, and afterward the intact beta and gamma phosphate groups may not be preserved to release energy. So the reverse direction costs more energy. In economics terms, the production cost is higher.

dNTP

And dNTP itself is synthesized from glucose and fatty acids, which connects sugar metabolism to fat metabolism. In fact, the entire pathway serves DNA/RNA replication (metabolism) – that is the true knowledge framework of biochemistry.

Back in school, the professor just went through each knowledge point by the book without connecting them into a coherent system. The mysteries of life were reduced to introductory facts from a biology survey course. The real essence lies in integrating the entire system. Like Po in Kung Fu Panda – before learning chi, he was just a formidable fighter. Once he truly mastered chi (the knowledge framework), he became a grandmaster.