Don’t take your toilet shut-off valve for granted. Make sure it still moves regularly, preferably when you’re not millimeters away from getting shit water all over your floor and feet.
Never leave anything on the toilet tank lid - you may someday have to rush to get it off so that you can push the flapper down and stop any more water from going into the bowl.
I went to check on the valve after reading this comment and apparently it takes hulk strength to move it even a tiny bit. Thanks for making me aware of this. Will get that sorted today.