1,000,000% this. If a senior engineer can’t explain it to you in a way you understand - even if you are a lot less experienced - that’s THEIR deficiency. Not yours. When this happens, it means THEY actually don’t understand it well enough.https://twitter.com/noahsussman/status/1170870234066165760 …
as a senior dev i agree with this 
! there are things i "understand" well enough to do, but not well enough to explain and when that happens it's always my lack of understanding at fault, not the junior dev. this also makes me appreciate teachers even more 