There is a world of difference between stumbling upon, knowing about in general and being proficient with -because of using on regular basis- some tech piece.

There is a world of difference between stumbling upon, knowing about in general and being proficient with -because of using on regular basis- some tech piece. I do know how bitwise AND, NOT, OR, XOR work but I don't solve problems on day to day basis that use those. If you give me two bytes to do the operations manually it is going to be a piece of cake for me. If you give me a problem where most optimal solution is using combination of those operations I most likely will use other solution that won't be optimal because on my day to day work I use totally different things. A bit of a tangent is that is also why we have "loads of applicants willing to do tech jobs" and at the same time "skilled workers shortage" - if company needs someone who can solve optimally problems with bitwise operations "right here right now", I am not the candidate, given couple of months working on those problems I would get proficient rather fast - but no one wants to wait couple of months ;)