Been there, done that. But there's always time for new challenges.
Currently trying to relearn C++(11) after some years in an isolation bubble in which all interesting C++ features were forbidden. Turns out the language is Not So Bad After All. Although I haven't yet decided whether it's Good Enough to be Worth Criticizing.
The best algorithm is one whose beauty makes you gasp for breath. My lifelong ambition is to have one of those named after me; meanwhile, I collect other people's.