I wish I had any other interest apart from programming...
I don't have too many hobbies myself, and TBH love programming and staying on the steep learning curve. Felt that way my whole working life.
The only time I've felt burnout is part of a 50/50 company where the other guy wasn't pulling his weight. When the energy you put in isn't giving you something back in the form of [whichever pursuits of happiness you have], then it's definitely time to re-consider.