Man who frequents Sainsbury's Camden and talks to himself out loud

Hi everyone, I moved to Camden 9 months ago and noticed a gentleman who frequently shops at the large sainsbury's in Camden.

He typically walks around the supermarket in small circles and talks out loud to himself in an English accent and is very articulate. He talks about a variety of topics including politics. You can hear him from across the store. He also has one of those shopping carts.

Does anybody know his story? I find him fascinating.

He also feeds the pigeons outside.