This is because of such questions at the interview and self-esteem decreases. You can write code that works and even works well, you will want to get a job where they want you to do the same thing you did before, but definitely someone should ask “how to get down from a square hole with only X meters round and which of them will burn faster?” Then, after an overwhelming interview, you’ll look at forums where hundreds of people argue how it’s better to solve it—through the Miclocho-McClay indexes or Freeman’s Uncertain Bubble, and you feel so insignificant—because not only don’t you know all these techniques, but you don’t even understand where and to whom all these skills can be useful.