I had to move in with my mom after a particularly bad period of misfortunes in 2002-2003 - up until then I'd been in and out of various living situations and jobs, and a short (and rent-free) stint with my grandparents. Living with my grandparents drove me crazy, sweet as they are. Living with my mom is like living with a roommate. We get along fine, we don't get overinvolved in each other's lives (much) and sometimes we have a lot of fun together. There are times when we don't get along, but those are few and far between. I am moving out of this house again eventually - it's taken me a long time to get back on my feet and back into a stable job again, get my finances sorted out, etc.
But if you know you can't do it, don't. My cousin made that mistake with her toxic mother - didn't let her move into her place (it's too small for 3 people, as it's a studio), but told her there was an empty apartment at her complex. She's lived to regret that one now, because her mother is driving her crazy. That woman would test the patience of a saint, though, so that's not saying much (she's my uncle's psycho ex-wife)!