I have celiac disease, and I am extremely symptomatic with just small amounts so I don't "cheat" there. I've been glutened a few times and the effects were so bad that I haven't cheated with this, even though, knowing myself, I thought I would have given in to pizza by now.
So for paleo cheating, I don't consider myself strict paleo, just someone who has learned from experience that starches make me feel lousy. After I realized I have celiac disease, I quickly got bored with the celiac web groups and blogs, because all they wanted to do was replace every bit of sweet, starchy kind of everything, and I continue to naturally become averse to those kinds of "food."
So I avoid grains, but if on a rare occasion (like once every 3 or so months) I feel like eating spaghetti with rice noodles, I'll do it. I keep GF bread around, but I rarely eat it. I have to keep it frozen or the little loaves will go bad before I can use them. Sometimes, I'll make a thin crust GF pizza, but most of the time, I stick with meat and veggies. Some of the condiments I use have sugars in them, but I'm getting more serious all the time about making my own and restricting the ingredients.
I used to be a real carb junkie but over the years, after doing low carb diets and seeing how I felt, they just aren't as compelling. Years ago, before I realized I have celiac, I bought a bread machine. The novelty wore off more quickly than I expected. I can't explain why I find it easy to walk away form this stuff when I had no control in the past, but it's a transition I made. I think part of it is that wanting to feel good more than wanting food to improve my mood might be part of it, along with finding other ways to feel emotionally satiated. Maybe because I appreciate little things in my life and don't need food to activate those pleasure centers.
I've been through enough that I see diet as a process, not an all or nothing state of being. It's about figuring out what allows me to feel optimally healthy, and I don't believe there is one way that is going to work for everyone. I try to incorporate as many paleo concepts as possible, while also remembering that I'm NOT paleolithic man, I'm a product of my Northern/Eastern European relatives, who also had their own local adaptations and gene pool anomalies. That's why I incorporate the foods in my family's heritage (meaty cabbage or beet soups, pickled herring and other pickled items, etc) into my diet without the grains. I do what I want and don't worry about whether it's "cheating" or not. Our paleolithic ancestors likely didn't care about dietary "cheating" either.