a person who is fully grow or developed is what?

Yesterday while I was on a run, (walk with an occasional jog spurt) I saw ahead of me two little, adorable, freckle faced boys standing by their bikes. As I passed them they asked if I'd come help them get a rope out of a bike wheel they'd somehow managed to get caught. I went over and tried to help. For the life of me, I couldn't figure out how the rope even got in there, let alone how to get the rope out. Then one of them looked up at me and said, "should we go find an adult now?" I ignored him. I was determined to get the stupid rope out. Then after a few more minutes he tapped me on the shoulder and again said, "hey shouldn't we go find an adult?" I agreed and helped them walk the bike back to their house.  While I was walking away I thought to myself... (in this order)

a) how old do I look? 

b) did they think their mom was going to miraculously get the rope out? because I'm pretty sure I'm not an idiot, and it was going to have to be cut out. 

c) am I an idiot and would an "adult" be able to get it out?

d) should I feel bad they didn't consider me an adult?

e) I dont think I am an adult.  

Anyway i'm not entirely sure how to take this. I can't decide whether to be offended or flattered. I also can't decide what the definition of an adult is. Is there one? If there is one, and it's true that i'm not, I either need to embrace the fact that i'm not or I need to grow up. Or perhaps I shouldn't let a seven year old impact me so much.  I think as a kid I had an idea about what an adult was, and I was pretty off. Maybe a kids explanation of an adult isn't something I should take seriously. Or maybe I just look super young. None of this is making much sense.

So lets just turn to..... Modern Family. The episode when Alex says that if acting like an adult is acting like someone in her family, then it can't be that hard. Which I would love to put......here.......  but it doesn't appear to be on youtube. But I did manage to find every possible interview with the cast while looking.  Fun stuff. It turns out that Phil/Ty is even greater in real life. Is he an adult? Anyway, If we take the teachings of that show seriously, no one is ever an adult. So. Maybe i'm good. But thats a TV show, so maybe I should figure it out.