I carry a pretty damn minimal repair kit, and I've gone over 5,000 miles since my last flat, but I still carry a spare tube and a few patches on my tours.

If nothing else, for peace of mind. Hitch-hiking to the nearest town wouldn't be a big deal in most of the USA, but I'd rather bike that distance than drive it.

I carry 1 spare tube, 1 tire lever, a few applications of chain lube and half of a patch kit. If its a longer tour I might also bring a few hex keys, just in case.

I've only had one flat while touring. It made me laugh more than anything. 700 mile ride from my new home town to my old one to visit friends, and it happens in the last town outside of my destination.