Poem on someone's birthday

(Before you criticize this, think of Rhymin' Hyman Pressman...)

Today is someone's birthday
But, you probably ask, whose?
In this poem I won't say
But I'll try to drop some clues.

When he counted his comic books on the hallway floor, he
Probably never counted on so quickly turning forty.

When he got his first glasses, which made him look kind of funny,
He didn't think that one day he'd be seeing twenty-twenty.

When he sat in his chair in the dorm and said, "Enter",
He didn't consider the day he'd be thirty and ten, or

When he went with my future sis-in-law on their first date, he
Probably didn't think about the date he'd be half-eighty.

He's now an XL but he's not that big a guy;
Now he fits just fine between XXXIX and XLI.