I actually have two Eddie headcanons ( not sure if that's okay to submit 2 at once)
The first one being that he might have the fear of needles like he may either retreat to a corner of wherever he is or just plainly faints at the sight of one. Possibly steming from a childhood bad experience with doctors and needles. Now he doesn't quite remember it but the feelings are still there.
The other is that (and this is a silly one) Eddie gets bored enough that he just counts the tiles on either the ceiling or the floor. Either way,there are times he lost count and had to start over again.
Howdy: Hm, now I just need to count the amount of replacement tiles I need to order-
Eddie: You have eighty-two and a half tiles on the shop floor, thirty in the janitor closet and fifty-five and three quarters in the break room!
Howdy: ...Eddie, why do you know that?
Eddie: I like to count them while you check over your orders.
Howdy: How do you remember all that, but can never remember where you placed your mailbag during lunchbreak?