to know or not to know?

I had a debate with a couple of Rats yesterday which I thought I'd share here. I'll pass on how many times I begged for the conversation to change from "does masturbating before sleeping wake you up or help you sleep" and dive right into the slightly more interesting part.
The issue was whether or not we would rather know if our ex is seen with someone else, has someone else in their life, etc... It's actually an interesting question because I've seen many different schools of thought on the topic. Now my friend the Masochist immediately said he wants to know everything, all the grim little details, and he wants to hurt as much as he is supposed to. Why? Because he believes you can't get over someone unless you hit rock bottom. He would rather get rid of every possible bad feeling, so that there are no more surprises later on. I thought he had a point --if you like to make yourself suffer, which obviously, as his name indicates, he does.
Some think that finding out your ex is with someone else will make them realize whether or not they want them back. I had a friend who broke up with his girlfriend, was moving on and living his life just fine, until one day he found out that she's dating some dude. He went crazy. He literarily couldn't stop thinking about her anymore, decided he was ready to do anything to get her back, felt like he was willing to sacrifice all the things he never even thought of before. And it lasted about a month, until she was willing to give it another go and he suddenly didn't want to anymore --again. What happened? He didn't realize that the whole can't-sleep-can't-eat process he went through was just an ego-bruise. And this tends to happen when you're the one who leaves your partner, believing they love you more than anything, and turn around to see them moving on with someone else. It's not your heart that hurts at that moment --it's that arrogant ego of ours that just cannot believe she could move on from the Extraordinary Moi. But in the heat of the moment, it's confusing, it makes us act irrational, and usually makes us do something we end up regretting --like hurting the other person again and again.
Now I'm from the school of thought that says "what you don't know can't hurt you." It may seem weak and cowardly, but honestly, I don't want to be hurt --so I don't want to know. Caporal said he agreed with me, but we usually end up knowing sooner or later, so we might as well take the hit. I disagree. I would rather know later, when I'm a lot more emotionally stable to handle it. Some of us think we can avoid getting hurt by never dealing with it. Others believe taking the blow and feeling the pain will make it go once and for all. I guess it all depends on who we are.