During a discussion in an informal seminar, someone asked why the speaker could make certain assumptions. A colleague and I offered two different, correct explanations. His was a more standard explanation that just hadn't occurred to me at the time. Mine was based off of techniques in the class I am teaching (nothing fancy, I'm teaching a required class for juniors and seniors).
Thinking about it later, I realized that if this discussion had occurred last year, I probably would have given a third explanation, motivated by the techniques I was teaching then. I happen to be a bit of a generalist, so I've had an opportunity to teach classes in 3 of the 4 major subfields in this department.
But this got me wondering, does this happen to anyone else?