What I've learned from past discussions here is that you have to be in love with the the instrument and/or know what you want to play on it. That's why my guitar never went far, I didn't have anything I really wanted to do with it.

I haven't managed to learn an instrument yet. I'm sort of working on Pennywhistle because it was a minor monetary investment & did not seem outrageously difficult. I've mastered it to the extent of playing hymns, but not real Irish music. I can do those hymns because I want to play them on something & the pennywhistle is what I have.