Help me understand this Sumerian joke

[nitpick] The Sumerians used clay tablets, not stone [/nitpick]

I dunno, Dave Barry has never steered me wrong:

“Archaeologists found this joke in an Egyptian tomb:
HE: Did you hear about the Sumerian?
SHE: No. What about the Sumerian?
HE: He was extremely stupid. Ha ha!
SHE: No, I had not heard about him.”

– Dave Barry’s Greatest Hits

McCoy: I know the place, Jim.
Scotty: Let’s go see!

I’m not a historian at all. I’m going to take this joke at face value, and I’ll tell you why I think it’s hilarious.

A dog walks into a bar. He says that he can’t see a thing.

Of course he can’t. He’s on all fours, and the drinks are behind the counter which is too high for him.

He decides that he will open “this one.”

Since he can’t see his options, he must choose a bottle at random.

There are a lot of absurdities here. How does the dog go from not being able to see the bottles to actually opening one? He can’t ask the bartender because he’s a dog. He has to do it himself. He jumps across the bar and takes a bottle. This is a very funny situation for a dog to be in. It’s way funnier than that old picture of dogs playing poker. That’s my opinion, at least.

This is classic dog comedy that has survived for thousands of years written by an ancient Sumaran comedian. Well done, ancient guy.

And the bartender snatches up his razors because here comes free hair of the dog.