Lesson One:  How Not to Put Up an Adhesive Ceiling.
If you look closely you will see that I've created a really unwise way to keep the ceiling tiles up and in place while the adhesive dries.  At the top you will notice a loose 4' length of 2X4.  It in turn is wedged into place without the aid of nails by a 6' vertical length.  Below that is a loose block followed by two busted up scraps of dry wall, and all of this is precariously balanced on a wobbly footstool.
If left to be it isn't that dangerous, however I'm working around it (while watching TV, no less) so what we have is a recipe for a concussion. I can't tell you how many times I've accidentally nudged it, noted movement out of my peripherals vision and had to rival Mikhail Barishnikov as I flung myself out of harm's way over exercise equipment and sharp, deadly power tools.  
(I doubt Barishnikov screamed like a little girl, though.)