Can it be happening?

Can Zach really be turning 4? It's funny because he's so tall for his age, that sometimes I forget that he's only 3 1/2. I tend to expect more from him, probably because he's the oldest. I know this is all part of the birth order, but I'm really trying to not do that to him. I don't want him to feel like he has too much responsibility and can't have fun, but I also don't want him to be irresponsible and create bad habits. I suppose this is all the balance of parenting...I just can't believe I've been doing this for almost FOUR years!!!! It's incredible to me!

Here's his 4th Birthday Party Invitations...