Opening the book…
Being the smartest person in every room is a symptom, not an achievement — it means you stopped putting yourself where you could be outclassed. Having a teacher keeps you humble and moving; having a student forces you to say what you know clearly enough to be checked. Lose either end and your knowledge starts to fossilise.
Name them. If you can't name who is currently teaching you something, go find someone better than you at one specific thing and ask for their time on a real problem. If you can't name who you're bringing along, offer a junior person standing time on your calendar and give them the actual work, not the scraps.
During grief, illness, or a period where survival takes everything you have, drop the teaching end and just get through. And don't manufacture a mentee for the look of it — an unwanted student is a burden to both of you.