The thing about being able to form permanent habits in a few weeks is apparently an urban myth. The real number is closer to 1 year.
I don't think I've ever managed to maintain anything for as long as a year without it already being a habit to begin with.
If it takes a year to form a new habit, I don't see how I'm ever going to manage to introduce any new habits at all. I get tired of doing things repeatedly way sooner than that.