Jo,
I wouldn't necessarily say that you will be disappointed most of the times you eat, but my experience after doing this for a while is that it has turned me into a definite food snob. When you eat quality foods, you train your palate to expect quality foods. That is one of the reasons I do so much of my own cooking--I just find that most restaurant food isn't up to my standards.
I used to have a friend that hung out over at my house a lot. He would have dinner with me 3 or 4 nights a week. He was single and had been perfectly happy with typical bachelor fare--burgers, fried chicken, frozen burritos, etc. After about a month he told me that I had ruined food for him, LOL--the stuff he used to eat just didn't taste good to him anymore.
So, the bottom line is, I still like food A LOT, but I don't necessarily expect to find "the best food I've ever eaten" in a restaurant. Especially where we live
And I am feeling a little better today