One of the first tricks most kids learn on a bike is the "curb grind". Riding parallel to the curb, the rider lifts the front wheel of the bike and swings it up onto the curb, while grinding the rear wheel against the concrete. (Not to be confused with peg-grinding, in freestyle riding, by the way.)
One day, not long after I had moved to Columbus, Ohio, I was out on my Motiv mountain bike, riding down the street, not far from the Residence Inn we were living in. I don't remember where I was heading, but I needed to turn left to get there, and the road I was on was a four-lane, with a raised center median.
I looked over my shoulder and saw a gap in traffic. So, I took advantage of the gap to swing into the left lane, with a plan to jump up on the median and then cross the oncoming lanes when a gap appeared in traffic.
I sprinted over, and noticed that my CatEye cyclometer was registering 20 mph.
"Cool!" I thought as I jumped up onto the median. Almost.
I didn't quite get the rear wheel high enough, and only the front wheel made it up onto the curb. Suddenly, I was doing a 20 mph curb grind with fast-moving traffic quickly overtaking me. I was really hoping I wouldn't end up high-siding out into the street.
Luckily, as I slowed, I was able to pop the rear wheel up to the same surface as the front, and I made my left turn with no problems.
No problems, but, I had plenty of adrenaline flowing!