'Hello,' I said.
'Suh,' said the old man.
I thought about asking him not to call me sir, but I couldn't think of a way to put it that might not cause offence. 'Nice fish'.
He nodded and grinned. 'Ornamental carp. Brought here all the way from China.'
We watched them swim around the little pool.
'I wonder if they get bored...'
He shook his head. 'My grandson, he's an ichthyologist, you know what that is?'
'Uh-huh. He says they only got a memory that's like thirty seconds long. So they swim around the pool, it's always a surprise to them, going "I never been here before." They meet another fish they known for a hundred years, they say, 'Who are you, stranger?"' - Neil Gaiman, The Goldfish Pool and Other Stories, Smoke and Mirrors .
We can see the same person everyday and still haven't a clue who he or she is....