Not everyone has the luxury or capacity to research and learn. So if you have a health problem you self diagnose and give yourself treatment at the hospital? I’m sure those docs get asked about the same problems all the time. And yet, they don’t turn you away because they have seen that problem too many times.

Built my first pc around the same time, and I still researched and asked for clarifications when needed.

I think you just have an issue accepting that others are not in the same situation or as capable as you. Some people have much less free time. Less tolerance for error.

Let’s say your engine costs 25k to rebuild. You’d do that yourself? Sans the labour, 10k in parts. You’re okay with not having a vehicle for potentially months? You’re okay if you happen to misunderstand an instruction or forget something and spend all thy time getting it back together advancing the thing explode when you get it all together?