Counting is easy when that's all you're doing.

If it's my turn in the bin, I have to count all of the luggage and other stuff loaded onto the airplane. No big deal, counting is pretty straight-forward - and the bins can't really hold more than 75 or 80 bags. You wouldn't think it would be difficult at all. But here's my brain stacking a 35 bagger:

"1, 2, 3, 4 - God that's an ugly bag, 5, 6 - oh great, here comes some of those huge-ass duffel bags, 7, must be from Wisconsin, 8, 9 - oops - that's a Heavy bag, 8 and 1, 9 and 1, 10 and 1, 11 and 1 - what's that down there? Freight? 12 and 1, 13 and 1, 14 and 1 - crap, it's another Heavy bag, 13 and 2, 14 and 2, 15 and 2 - how does that bag NOT have a Heavy tag on it? It's heavier than the 2 marked Heavy bags put together!, 16 and 2, 17 and 2, 18 and 2 - oh great, here come the golf clubs - where should I put those?, 19 and 2, 20 and 2, 21 and 2 - whew, cart's empty, I can take a breather while Mike switches them - where was I? Oh yeah, 21 and 2, 21 and 2, 21 and 2, Blackjack and a deuce, Blackjack and a deuce, Geez Vegas is fun, Blackjack and a deuce, baby! - here come more bags, 22 and 2, 23 and 2, 24 and 2 - gotta love car seats, 25 and 2 - here comes a Heavy bag, 26 and 2, 27 and 3, 28 and 3 - getting crowded in here, 29 and 3, 30 and 3, 31 and 3 - almost done, 31 and 3 - and now for the freight, 31 and 3 and 2 @ 75 pounds - I'll just fill in the bag card and we can close up the bin - done and done!" 

Of course, the second I fill in the bag card, the last bag shows up. 

Then it's on to the Planeside bags (or carry-ons, but that name implies you would, in fact, carry them on. Which some passengers do, insisting they'll fit in the overhead bin, which they never do - but we'll save that for another post).

The Planeside bags are easy to count, because they're not moving:

"1, 2, 3, 4, 5, 6 - how much time do we have? D'oh, I can't see the board from here, 7, 8, 9 - better hurry up, 10, 11, 12, 13, 14 - #$%& STROLLERS!, 15, 16, 17, 18. Counted and loaded, now just fill out the rest of the bag card, give it to the crew, and this bird is ready to fly."

Which is exactly when the gate agent signals that there were a couple of "carry-ons" that didn't fit in the overhead bin.

I think I do a pretty good job of counting for someone with my short attention span. Hey, puppies...