Same for me - 8 years of piano with regular exams, gave it up in my teens because I didn't want to play just classical stuff, and all that practicing was just plain boring. Haven't touched a keyboard since (and have carefully forgotten all that music theory).
I did pick up an old classical guitar at a girlfriend's house and started on Simon and Garfunkel and Beatles, and have been playing guitar (and bass, mandolin, slide guitar and lap steel) for the past 45 years, so the music was there!
Having brought up 3 kids, it is sometimes hard to know when to encourage them to push through on something and when to let it die.