Back in the days as a junior analyst at McKinsey you would often see a deck or listen to a presentation that you would not understand completely. Being 23, I usually kept quiet and assumed that this was my problem, not the presenter's.

Now at more than double that age, I still have the same issue: I often don't get why something is so special, so unique, so difficult to do from reading a slide or listening to the presenter. My IQ has not changed much (it probably got worse), and yes I have learned things, but the biggest difference that I have gained the confidence to know that it is not my fault. It is OK to ask a question that might sound trivial.