My first skate demonstration

So I walk into school today, with my board in hand. As I'm walking up to the second floor, Uncle Sam (more about this character later), enthusiastically asks me if I can skateboard. I reply that I can so he asks me to show him. "Here?" I ask. "Yea, in the hall." I lay the skateboard on the floor, place my right foot in the center and give it a good push with my left. I move about an inch until the wheels are blocked from spinning by something probably left on the floor by a half day student. I go flying forward with my soup and subway sandwich in my hands, the board shooting backwards off into the stairway. Clonk, bonk, tumble, tumble, tumble. Uncle Sam screaming "Oh my god! Are you okay?!" Besides some of the soup splashing onto my pants, I was fine. I think the sandwich helped break my fall. I'm just glad I didn't take some poor kid's head off with the board flying into the stairs. I tried it again without difficulty; whatever that was on the floor obstructing the wheels, mysteriously disappeared. Then, he asked if he could try it. He gave a slight push and jumped off, "My God, so dangerous!" Completely flush red embarrassed, I headed up to the prep room.
Uncle Sam is an interesting fellow who's been working at Kojen School #6 since it opened some 15 years ago. I'm not really sure what his position is and I don't think anyone else at school does either. Sometimes I see him in the stock room filling forms out or in the office writing important things, I'm not sure. But then I also see him fixing lights and sorting the recycling bins. He's the nicest old chap who always says hello when I walk by but I'm not quite sure why he works here. What I do know of him, beside the fact that he's an unbelievable ping pong player (just recently winning the fourth consecutive annual table tennis tournament at our school,) is that owns several apartments and properties around the city of Taipei. Saying he's more than well off is an understatement. He's just loaded, though, you would never have guessed it by his modest manner. I just hope I don't embarrass myself too badly in front of him any time again in the near future.