After a couple of decades as a self-taught "hack" musician, I made a resolution last New Years to go and actually take formal music lessons. I've had to unlearn some really bad habits in the 12 months since, but it's been paying off and has really given me a new appreciation for "professional" musicians who actually know what they're doing. 😜
My only regret is I wish'd I'd undertaken this when I was much, much younger! Ha!