I just had to laugh when I saw the topic of this thread. Granted, I was imagining cats just slamming themselves into walls! LOL LOL
Hey, it could happen. Cat are...after all, cats...and their behaviors are sometimes a mystery! LOL LOL

But, I really can relate to the accidental crash into an object when they're just moving too fast to stop in time! I know I shouldn't laugh at my baby's misfortune...but it's hard not to laugh!

The situation almost always goes something like this:

thumpity, thumpity, thumpity, thumpity, thumpity, thumpity, thumpity, thumpity, thumpity, thumpity, thumpity, thumpity, thumpity, thumpity, thumpity, thumpity (imagine a heard of elephants running through your house...and that's what it sounds like when my cats are doing that! LOL )
.........SCREEEEEEEEEEECH....THUD!

resulting in...
confused cat acting like he meant to do that...