I have the same issues as Mimi. I can do the skewer, get the tire off, put the new tube back in (have even done this for friends who couldn't). I have put the rear back on while practicing in the numerous workshops I have been to, but any time I have practiced at home, my bike ends up in pieces, with the chain lying on the ground. I don't like riding alone because of this. It's very hard for me to remember exactly what to do... I have a great memory for other things, but if it's steps in a mechanical process or math problem, forget it. Plus, it's very hard for me to visualize anything and I have no spatial ability.
But, my goal for this year is to feel confident with this after ten years of riding.