Exercise you actually kept doing

Not the one that worked for six weeks. Most exercise habits fail within the first few months — not from lack of willpower, but because the activity itself wasn't actually enjoyable, or it depended on motivation instead of a routine nothing else competed with. The habits that survive years usually have something in common: they're social, or scheduled at a time nothing else touches, or they stopped being about results and became just something you do. What's the one still happening two years later for you, and what made it different from all the ones that didn't stick?