"Erm... " you say.
"I'll give you some time to think about it, how about that?" the old man with a a hat on says.
"Wait, wait, wait," you say, almost reaching out to pull him back. "You can't just ask to come in then leave me there standing in the doorway considering! Who are you, anyway? Why should I let you in?"
"Why are you so rude to old people?" the old man says back.
You look back at him, offended. "I am not rude to old people."
"Tell me one example, then."
"Well, I only poured a bucket of water over my grandma. See? I'm nice to them. I didn't even pour syrup, just water." You smile smugly. "See?"
"Huh," the old man says, then starts shuffling away.
"Why did you ring my doorbell, then, if you're going to walk away like that?"
The old man looks back at you. "My days of walking are over. Now, I can only crawl to and fro." Then he continues crawling away from you.