While my grocery shopping is strongly determined by nutritional label content, my behavior at restaurants only weakly is, and I think this is related to the fact that so few restaurants offer that service in the first place. If I'm going to a restaurant at all, I'm in the habit of taking for granted that I will only be able to guess at the nutritional content of the meal I'm ordering, and will therefore be taking a break from deciding on the basis of labeling (as an aside, I have an enormous appetite, and can eat a meal meant for three and have room for dessert afterwards despite weighing under 75 kg. I'm used to eating until I'm only fractionally full, but will sometimes have "break" meals at restaurants or on holidays, so my restaurant eating isn't that indicative of my usual diet.)
If restaurants routinely listed caloric content of their menu items, instead of the places that do so mostly being fast food chains which I tend to avoid in the first place due to their reputations for low quality and unhealthy food, it might be a significantly stronger determining factor in what I order.
ETA: When I was mostly reliant on a college cafeteria for food (which is in many ways more similar to a restaurant than a grocery,) I was strictly dependent on nutrition labels to choose what I ate, and if anything was unlabeled, or I suspected it was mislabeled, I wouldn't eat it.
Information that surprises you is interesting as it exposes where you have been miscalibrated, and allows you to correct for that.
I suspect the users of LessWrong have fairly similar beliefs, so it is probable that information that has surprised you would surprise others here, so it would be useful for them if you shared them.
Example: In a discussion with a friend recently I realised I had massively miscalibrated on the percentage of the UK population who shared my beliefs on certain subjects, in general the population was far more conservative than I had expected.
In retrospect I was assuming my own personal experience was more representative than it was, even when attempting to correct for that.