Lol - darn, I am busy that day, whichever one it is......
When we purchased the house, two bedrooms, 2 hallways, 1 "TV" room and a bath all had textured walls. Wife don't like textured walls so as you may have guessed, it was time to skim coat and smooth. We did all of them except this hall without the slightest problem. That is what really baffled me - I think I went through 12 of the 5 gallon buckets and then this. Was really weird.
I done a lot of regular drywall and must say it is one of my least favorite jobs. The mess it makes is a royal pain. Seems you cant contain it, it gets in every room, no matter what you do. I always tape stuff off, hang plastic, shut off the HVAC, but somehow it sneaks out and lands on everything.
Hopefully in the garage you can open the door and put a big fan to pull the dust out and away from you and the living space. Good luck