I’ve had the privilege to have mentored a handful of engineers in my career. I grew fond and protective of them. They are all extended family. Naturally, they were all different. Some needed insight into how to debug a particular problem. Others asked about the history of a particular component and why it behaved the way it did. I rank designing components with them among the most fun and rewarding activities.
Engineers consistently learn best by ‘doing’. As I mentored them, I instructed them to feel free bang their heads against the wall for a while; solving that puzzle will both best commit it to memory and boost their self-confidence. However, we also set healthy boundaries for how long they may struggle with that puzzle. I advised them to come get me if they had not made any progress for a while. We set our rule of thumb to two hours.