I get knocked down

I'm angry. Not just angry, jealous and confused.
Tonight: Friend on Facebook writes about her daughter who isn't even a year took her first unassisted two steps.
Earlier this evening: Picture me trying to coax Vincent into pulling up. PULLING UP! He throws a fit when we make him stand, let alone try to get him interested in anything beyond that. It's baffling to be a parent of a child who isn't curious and eager enough to want to do things on his own. He'd rather sit back and watch all the other kids, or lately, have us participate with him. The therapists tell us that though Vincent has low muscle tone, much of it is his personality. He has to be ready to make the decision to try something out.
I know one day he'll be walking just fine and this will all be great story to tell the grandkids, but honestly, it pisses me off because in the meantime Vincent is missing out on a lot. At his daycare they won't let him progress to the toddler room to be with other kids his age because he can't walk. So he hangs out with babies all day who don't do a whole lot of interacting with him. They're also drinking from bottles (while he's drinking from a sippy cup) and eating baby food (he's eating table food), which he's fully aware is different. Some days I'm told he wants a bottle and their food. He doesn't understand why his is different. I worry that he has to play by himself a lot since babies aren't horribly social with one another, and maybe that's why he doesn't want to play by himself at home because after doing it all day, he's craving playing with his loving parents whom he can trust. I'm trying to be patient, but it breaks my heart some days.
I've found that the biggest part of parenting is accepting who your child is. Someday I could very well be accepting if my child is gay, a nerd, a loner, or some other quality that I don't fully understand. So while all of this is heartbreaking for me, Vincent is an amazing little boy who loves to cuddle and be held, who's hanging onto babyhood for dear life. Why am I so eager to push when he so clearly isn't ready? Why am I trying to change his fundamental nature? After all, who doesn't love a snugly kid?