Good to recognize stupid questions do exist but so does anxiety around asking necessary questions. The engineer I'm mentoring said they'd ask lot of stupid questions. But we're working through them. A lot of them were things I wondered too, like "this current reading doesn't make sense because the upstream supply is saying it's taking less current" but it was a nonlinear buck regulator. I offered to explain more but they just sat with it a minute, I offered again, but they said they were ok. My viewpoint is to give just a hint and then offer more so they can still go through the thought process on their own, which is really what I'm trying to teach.