The current course I'm taking for my master's degree is Probability Theory, and our instructor pointed out early on that it's a "calculus-based" probability theory course.
One part of the lesson I watched last night involved calculating a definite integral; the instructor skipped the intermediate steps, said something like "you can confirm this with u-substitution", wrote the answer, and moved on. Today I decided I needed to review u-substitution and integration by parts, as it's been a few decades. I got a calculus book and got to work reviewing, and after a few minutes decided to try last night's problem. Before starting, though, I called up a couple of my stats students who either have taken or are concurrently taking calculus, and asked them to make sure I didn't make any mistakes in the process.
While I solved the problem correctly, I think they enjoyed my soliciting their "help".