I overheard this mid level dev discussing a new task with a senior dev. They're discussing compile error in cmake. I realized that the mid level dev asked so many basic stuff that are easily google-able. Mind you, our codebase is cmake based, how come she didn't know even the basics and yet survive in our company for years?
I felt bad for the senior dev, as I knew he's busy with his work. He couldn't do his job because he had to do hand-holding with this dev.

My biggest mistake is often trying to solve things by myself which will take hours instead of just asking a senior. But asking other dev for every little things are also annoying. Why can't you just google shit up or RTFM?