I watched GroundHog Day in my mid-30s and was inspired to learn the piano. Stop laughing at the back. The fact is that you don't have to be good to enjoy yourself.
If you like Groundhog Day that much, you should check out the novel it was loosely inspired by, The Strange Life of Ivan Osokin by P.D. Ouspensky. Ouspensky isn't known as a novelist (he became a guru type) but up until the end where it gets a bit doctrinal, I thought it was a thoroughly delightful book. It's also a psychological tour de force, but I don't want to spoil the story by explaining why.
There's so much room for interpretation in this movie it's hard to know where to start. Consider, for instance, the fact that Murray's character apparently spends decades in this state.
My Dad started learning in his mid 70s.