I have fell up the stairs many times. Those are always special and painful reminders of the anti-gravity features to my home.
Totally unintentional pun on my part. Does that count as verbal clumsiness? 
When I was in high school, the bunch of us in PE were jogging back from whatever we’d been doing jumping over a chain across the road. The class clown would pull on the chain raising it a couple inches as we jumped over. Everybody did just fine but me. I hooked a foot on the chain and did an instant 90-degree spin and slammed my head into the pavement.
The next few minutes are kind of hazy. I remember being picked up by the arms and being unable to breathe with someone saying, “He’s just had the wind knocked out of him.” Some small part of my mind thought that was a very apt description.
After that I got nuthin’ until I come to under the shower what had to be a good five or ten minutes later. In those “suck it up times” I didn’t even get sent to the school nurse.
I know I’ve told this story before in the SDMB:
Several years ago I was helping a friend pack his belongings for a move. After loading the (very) first box, I picked up some tape to seal it. My friend did not have a pair of scissors handy, so he offered a small fillet knife to cut the tape. For some reason, I took the knife in my right hand and went to cut the tape I was holding in my left hand…and put the knife right into my forearm. I cut several tendons.
The worst part was that we had to drive to the emergency room. My friend didn’t have a car and he couldn’t drive my manual transmission, so I had to drive myself. (I know…I should have called an ambulance.) He reached across my lap to keep pressure on my left arm while I steered and shifted with my right. It took about 20 minutes.
The orthopedic surgeons had to open my arm from my wrist almost to my elbow to reattach the tendons. Fortunately, my fingers all work, but my left palm has been numb for many years.
A very, very clumsy and stupid thing to do.
One evening my wife and I met up with a friend at her place of work. A female co-worker of hers was taking a heavy bag of trash out back to throw into the dumpster. Me, being the gentleman that I am, offered to take it out for her. She came with me to show me which dumpster to throw it into.
I gave the bag a heave before I threw it into the dumpster (which was about 6-7 feet high), and when I did, the bag split open and trash and trash juice shot all over this woman. It wasn’t exactly my fault, but I still felt so embarassed. Luckily, it was the end of her work day, so she could leave right away.
Two years later, I did the very same thing.
The struggle is real, man.
Not really a tale of clumsiness, though the OP in the link contains one about my dad, but I guess a 'Tale of DOH! :smack: ’ might go in this thread.
Yesterday I got out my dad’s Vulcain Cricket watch. It’s 50 or 60 years old, and it ticked away when I shook it. The alarm, which was on, worked when I set the time. I wore it all morning to wind it up, but I noticed a couple of times that it had stopped. What? But it was running so well! 
I thought I might have to take it to the watch-repair guy. Then it occurred to me…
The movement isn’t automatic. :smack:
Kinda like when I watched a pre-schooler use the touch screen on her paper picture book.
The motor on the driver-side window is automatic. Once pressed, it rolls all the way up whether or not you continue pressing on the switch.
Before driving off I rolled down the window to exchange question/answer with wife. Noticing window was down I absent-mindedly pressed the up switch. Before retracting head. I mentioned the resulting headaches, though embarrassed to mention the cause, in an IMHO thread with a title like “Headaches, should I get CT scan?” (Doctor was far more worried about my swallowing problem — do I have esophogeal cancer? :eek: )
I’m so clumsy I sometimes close a door right on my finger! This was only a minor annoyance … until I closed the door right on top of the thumb a bumblebee had stung the day before. :eek: (I’m much more careful about a lot of things these days.)
Dropped a round (#pricey) lightbulb I was putting in the light bar in my bathroom. It broke allover the pedestal sink and the floor. Of course I cut my finger cleaning the mess up. You can’t exactly use a broom and dustpan in a sink. Finally got all the shards cleaned up and turned to put the little trash can down and stepped on the screw end of the bulb and cut my foot. Arrgghhhhh!
Got a new one this morning. I cut my nose while shaving.
Shaving is one of those things where I constantly have to tell myself to slow down, because if I don’t then I get a little careless. Like this morning. Going up to shave my upper lip, and caught the edge of my nostril with the razor. 45 minutes later and I still can’t get it to stop bleeding. And it’s not really somewhere that I can stick a band-aid. I guess I’m going to be walking around holding a kleenex to my nose all morning. The drive to work should be interesting…
Wow. One of my dorm mates had something similar happen while sleeping in a loft bed, but she just rolled out of bed and landed on the floor. If I recall correctly she broke her arm. The hall director had to bring her to the er in the middle of the night.
My older sister and I shared a bunk bed when we were in Japan. When we got back to the States, we each had our own room and I got the bunk bed. One night I was sleeping in the top bunk. I neglected to put the guard rail up. I rolled over in the night and had the most bizarre vision of the floor coming up at me. I hit it flat on my stomach and had the wind partially knocked out of me.
I crawled into the lower bunk and slept there the rest of the night.