How can engine run cooler than thermostat rating

I have talked with a few other car nuts and have heard this comment. "I run a 195 degree thermostat and my car runs 180-185 all day". I don't see how this is possible. I know the engine is circulating water but, wont the engine eventually reach 195, open up and let cool water from radiator in, then climb back to 195.

Can someone point me to a technical site that has a good explanation?

Also, at what temperature should the radiator build pressure?

Thanks FABO experts.