I remember a long time ago when I was young...I used to think that fitness or yoga was something you could achieve. I didn't really "get" that yoga was something that had to be kept up in order to keep getting the benefits from. I guess after universtity, where there was a lot of achieving, I wasn't used to the idea that you'd have to keep practising. I started yoga while I was in university and then carried on at Kripalu after doing a bit in Asia. I remember Bikram saying that he didn't need to practise yoga anymore because he'd invested so much time doing it. That was a long time ago, so I don't know if he'd be saying the same thing now, but that's what he said 15 years ago.
I heard a joke a while back, "the trouble with vacuuming is every six months you have to do it again." I think about yoga like that. It has to be kept up or we can fall apart. Or like laundry. You have to do it regularly. You don't do your laundry once and then it's all done. It's something that, when kept up, can keep you sane and feeling more comfortable.