I don't have kids but I understand the level of energy they take, and I know where you are coming from. I've don't really know what it's like to feel young, and I often imagine all of the things I would have done in my life if I didn't have MC. When I was a kid I wanted to skateboard, and BMX, and ski jumping looks pretty fun too. I definitely would have joined the military....I tried to get to a point that I could but it was a losing battle, and it just would have been nice to have the level of energy and mobility of other people.
I don't really expect other people to really understand the disorder, because most people can't really understand that which they can't see and have never experienced, but I do ask them to just take my word when I say I can't do something.
If you go to the top and do a search by typing in the word Expectations, you will encounter a thread that I began, and to which Jan and Jenna and others responded. It has helped me a great deal, and I even copied the post, printed it, and gave it to my children. I hope it helps. Don't give up on yourself, no matter what others say. You have many who understand. I believe we "step up our game" every time we do anything at all that is normal for most people.