Why Does This Keep Happening?

The closest thing I have to a reoccurring dream is the one where I’m naked and no one notices at first. When I was a teenager the dream went like this:
I’m sitting at a desk taking a test. I’m in high school. Everybody’s looking down at their test. I’m looking down at my test. Then I realize I don’t have any pants on. I’m naked from the waist down. How did I let this happen? How am I going to get out of here and get some pants on before someone sees me? Any minute now somebody’s gonna look up…
I always woke up before anyone saw me. In my late 30′s I started working at a coffeehouse and I was feeling pretty confident with myself. When I had the naked dream again, it went like this:
I am outside my college dorm room. I am not afraid. I am buck naked and I’m running across campus. A handful of people see me and say ‘Dave! This is NOT cool!’ to which I respond ‘I know some people who would think this is REALLY cool!’ Of course I’m thinking of my coffeehouse friend who has just made a snow penis in my front yard.
I am now 54 years old. Friday night I had the most recent version of this dream:
I’m at a gift shop where no one speaks English. I am completely naked again. How does this keep happening? The guy at the register has swimming trunks for sale, but they are all too small and I have no money. I sit down and grab some newspapers to cover my mid-section. A security guard asks me why I’m naked. A handful of people talk to him on my behalf and point at a large man who is offering me his underwear. He will keep his pants and go commando, and I will wear his underwear. His pants don’t smell fresh– but they don’t stink either. I will gladly wear his underwear.