Birthday party invitations

It's one of those universal things that moms to ASD kids worry about. Party invitations. They seem to go out ot everyone but our kids. I've heard enough moms' stories to know that kids don't like to invite the "weird kid who hits/throws tantrums/talks about dinosaurs nonstop" to their parties.
So maybe this is why my heart skipped once when I saw the small white envelope in my son's backpack.
And then I thought, how stupid of me. This happens all the time.
Thank you notes and party invitations look exactly alike, size-wise.
Too many times I have pulled an envelope out of my son's backpack/cubby/folder and gotten that same little jump, only to open it and find a nice thank you note from a teacher or aide. Sweet, but disappointing.
Today though. Today was a real-life birthday card.
I asked Monster, "Who is A___?" and he said, "Oh, he's my friend!! He's in my homeroom class!"
And I raced to that phone and called and RSVP'ed before other parents had probably even found and opened their kids' envelope. I wonder if I sounded as foolishly overexcited as I felt?

Oh, my son has been invited to quite a few parties. But not from kids at daycare or school. This is the first. And I hope not the last. Because just because he got this one does not mean he's made it to the other side yet. But it's a start.
It's sad that I get so excited about something like this.
My son. Someone who knows him from school wants to have him at his party. This is wonderful.