I once set a homework task for my Year One students where they had to share a fact about the sea with the class. One of my students shared a fact that I'd heard before but couldn't quite remember where... Later that afternoon I was reminded of that same fact by my friend Libra, I had a bit of a chuckle (& shared it in the staffroom).
I'm now working with university students and that for me thinking about how one might reference that source....