Explain that you are actually 16 in the year 2015 but you were sent back in a time machine, and that real time travel alters your age to the state you were in at that time. This is why you can't travel to periods which you have not lived, because you don't exist at that point and for that reason you can only visit those times as a outside observer without a body to use to communicate with the strangers around you. This is also natures way to keep you from altering the past and destroying the future world. Then also explain that you are really not 16 but this is all a dream and he is asleep and you will simply go into the show because that is the path of his dream and he must not fight it. Then mention that it really isn't a dream and everything happening is 100% real. That you were walking through the wrong neighborhood and smoked a blunt with a nefarious character laced with dust, and now you're tripping so hard that you think you're 16. And if you're sure you're 16, that you really are 16 in your head which means they should allow you inside because you're the age that's required inside and that's what counts. But then explain that you didn't actually smoke pcp, and you are simply a 13 year old that wants to get inside the show and has some money with his name on it if he turns the other way and lets you in.
Chances are he'll either kill you or let you in before you even get halfway through that.