You know, even if the pattern is complicated, and there are some patterns that are really, really difficult, the concentration is so hard that it is a sort of meditation. Or mindfulness. Our grandmothers were not mathematicians but they were very good with creativity that necessitated counting, measuring, dividing, summing, multiplying.... etc. So I see more and more that knitting is not just an art by itself but much, much more!
I agree that knitting is an art and so much more. My paternal grandmother knitted but I was young when she died so never got the chance to learn from her.
I also agree that is a pattern is difficult it can be relaxing. That is as long as things are going right. I am working on a shawl right now that I was more then half done. I messed up and in trying to fix it made things worse and ended up frogging the whole thing and starting over again. I love the pattern though so it is not that much of a chore to restart it.