I have a room where I removed the wallpaper in preparation for painting. Surprisingly, the very old wallpaper just peeled right off, leaving behind most of it's glue. I used some wallpaper remover spray to quickly clean up the few spots where some of the backing paper stayed behind, so now the wall is just drywall covered almost entirely with a thin layer wall paper glue.
I tried using the wall paper remover to take off the glue, and it works well, but is tedious and time consuming (compared to how easily the wallpaper itself came off).
Is it really necessary to take off this glue? Will new primer and paint adhere to it as well as it would to the drywall or am I asking for trouble with premature peeling paint or other problems down the road?