Earlier this year I tried 30 days of yoga at home. My instructor never got tired, or expensive, or scary because she was a youtube video. At the end of the 30 days, I decided that I'd rather put more time into rock climbing than yoga. But I'm glad I tried, I've wanted to try yoga for years but never mustered up the energy to do it until now.
I think this illustrates two important learnings.
First, that having a set time period associated with a new behavior makes it easier to commit to that new behavior even when it's not obvious that it will be good.
Second, that by introducing a decision sometime in the future, you avoid the trap of continuing to do something that's not that helpful just because you started and never really considered whether it was worth continuing.