A prayer for the feeble-minded.

I had an interesting interaction today. An elderly gentleman came in today, wanting to order a to-go. The host directs him to me, so I greet him and the following exchange occurs:

Blondie: What would you like, sir?
Elderly Gentleman: I want dinner, but I don't want mashed potatoes.
B: Sure, you can replace that. What would you like for dinner?
EG: Good, can I get french fries instead?
B: Of course, but what is the entree?
EG: They've made it for me before, and it comes with a salad. I just don't want mashed potatoes.
B: Okay.. but... what do you want?
EG: I want dinner to go.
B: Okay, well you have to tell me what you want for dinner. Do you want to look at the menu?
EG: No, no, I had it before. I just don't want mashed potatoes, and I want a salad.

At this point I realize he's a little.. not all there. So I try to avoid getting frustrated and help him out.

B: Okay, do you want chicken, turkey, roast beef, a sandwich? What are you looking for?
EG: Yeah, sure, roast beef, and french fries and a salad.
B: Well, sir, I just want to make sure you're getting what you want, and I can't do that if you don't specify so I can tell the kitchen.
EG: They made it for me before. I just don't want mashed potatoes.

Now, I'm getting a little confused myself and my co-worker can see I'm starting to get annoyed, so she butts in and tells me he normally gets the roast chicken. I ask him if he wants that, and he's saying 'Yeah, sure, I just want dinner' again. I told my co-worker to just take it, because apparently she's waited on him before. She told me later he reminds her of her dad, whose brain is also a little fuddled. When he left, he gave her a 10 and me a 5, which I tried to refuse, but he insisted since "I got no better use for it and at least you tried!"
I hope I'm like that when I'm older. I mean, you can't take it with you when you go.