Do you think?

That I should let my soon to be 3 year old pick out his birthday theme?

Here's the problem with that...he wants his party to be 10 different things and I've tried explaining to him that he can only have one.

Quoting pr0ud m0mmy 0f 2:“ That I should let my soon to be 3 year old pick out his birthday theme? Here's the problem with that...he ... [snip!] ... problem with that...he wants his party to be 10 different things and I've tried explaining to him that he can only have one.”

Just pick a few options for him and then say "Pick ONE".
I did that for my son this year for Halloween (last year he picked it out before I even wanted to go get his costume lol)...and he got his choice of several options and he thought about it and picked Optimus Prime.

Maybe narrowing down choices and showing him pics or the item would help?

You could pick 2 of his favorite things, then let him chose between those 2.

lol that is so cute

I let my two year old pick. I laid out a bunch of different things and told him to pick one. If he picks more than one then you hold up each one and have him pick from there. Just keep narrowing down until you finally reach just one.

Maybe give him a choice bewteen 2?

Thanks momma. Well, I have choosen Little Champs birthday theme (since he'll playing soccer next spring) and Hot Wheels. I'm letting him and his dad choose 2 more than thinking about writing them on a piece of paper and letting him pick the number 1 through 4.