I say it only takes doing something ONCE for it to become a habit, when that thing is something indulgent and possibly bad for you. Like stopping for gelati every time I drive by the ice cream store.
I say it's easy to leave old habits behind when there are better alternatives. It's surprisingly easy to change my patterns, with a new location.
I live closer to the ballpark now, and since summer baseball has begun, I've been there a lot. (Last night, for example. When a huge zot of lightning was accompanied by a nearly simultaneous, extremely loud clap of thunder, I suddenly became highly aware that I was sitting on a metal seat under a metal canopy. Next thing I knew I was at home on the couch. Wow, that was fast.)
I'm also a whole lot closer to yoga now, making it ridiculously easy to swing by there at various morning and evening hours.
I'm a lot farther away from fast food. As a result, I've been eating at home more often, which translates into less fat and more salads.
All this self-improvement makes me sound virtuous, right? Don't be fooled. I'm as lazy as ever. It's just that I don't have to go out of my way now for the good stuff. Instead, the good stuff is delightfully nearby.
And the gelati store is no longer on the way home.