Okay. Stupid human tricks. I have 'em. The days of performing all but the simplest are past...but here. Try this.
Stand with your feet flat on the floor. Now, squat down without lifting your heels from the floor. Sounds simple, but a significant portion of the population can't do it. This isn't so much a stupid human trick as it is a trick of genetics. You're either born with hyper-open ankles or you're normal. This is the one I can still do.
The real trick was a blip corresponding with my three years at an acting conservatory. I was in the best physical condition of my life. It was nice while it lasted, so don't ask to see this in person. Someone'll just end up having to call 911.
Start in lotus position. Slip your hands through the gaps in your folded legs. Using the strength of your abdominal muscles, bring your knees as close to your shoulders as you can. Now. Hike forward and up on your hands. Walk. Climb stairs - this is the easy part. Now, turn around. Go back down - this is the bitch. But yes. I could do this. I DID do this for a show while still at Cornish. It amused my classmates. They already thought I was pretty hopelessly strange, so it was no big deal to confirm their suspicions in this fashion. Besides. It made the object of my unrequited affection at the time laugh, so I was all about it.