On a related note, every couple of years I make an effort to man page every cli tool I use, and re-read the man page, just in case. Most times I discover there is some argument that I've missed before in a tool (or has been added in the intervening time)
I hand rolled stuff in itertools/functools for years before discovering them.... collections Counter, etc.
Or how about str.partition instead of try: str.split() ?