Why is it so easy to confide in a stranger?

I've had a really interesting day today,and I'm not sure if it's for better of for worse,but a bit of the old me stepped out of hiding.
I guess it was doing a little bit of what I used to really enjoy; talking to new people. The method is a to be taken with a pinch of salt though,as it was on-line. Which I fully understand at the outset sounds very dodgy,and that seems to be most of the other peoples agendas. But the internet is just such a fantastic place, a place where people can meet from all over the world, why not talk and get to know new peoples, their cultures, hobbies and maybe troubles. I used to a lot when I was younger, and made lots of nice friends. I was a teenager then, and probably 80% who are on the site still are,aggressive, insulting and inexperienced (in pretty much all aspects of life!) but there were a few nuggets of conversation I had which were new, refreshing and actually pretty witty which was nice. I strangely found a bit of comfort in it.
Earlier today I met a nice guy,who seemed to be looking for the same thing as me; just a person to talk to. Being two strangers who shared a little, then went their separate ways.And I love that idea, people don't talk enough to each other and we've all got so many little quirks of our own and stories to tell. After getting past the awkward first couple of minuets he asked what weird things I may have done in my life, and then it went on to be a bit deeper. I found it so easy to be open and so brutally honest, it was so cathartic to read the truth plain in front of my eyes. He asked me to tell him something that I haven't told anybody before, and I did. 'I'm not as nice as people think that I am' is what I said, and went on to tell him what I haven't told anyone before. I was awaiting a sudden disconnection or an insult, which would have been fair enough. But he actually understood where I was coming from, which I thanked him for. And the chance that I could get something like that off my chest. Why is it so easy to confide in a stranger? I asked, and he said simply 'because you won't be judged.' I guess when talking to a complete stranger you don't have anything to lose.
We went on to talk about our jobs and then relationships. And it was amazing how much we shared. He was about 10 years older than me, and been with his partner for over 10 years, too settled to leave but frustrated at not being able to be more sexually adventurous. Although the time scale is a little different, I really feel the same way. It's probably how a lot of people feel in reality. But it was nice to actually hear somebody else talk about it.
It went on to him joking about having an online sexual relationship, which is of course a ridiculous idea and of course I couldn't honestly agree to it,but there was a piece of me that wanted to.It's the sort of thing I used to do with Ben back in the day, I didn't enjoy it because he was a forceful dick about it, but when I initiated it, it was fun. Maybe it's because of the dirty, sleazy image that's attached to it that makes it all the more appealing somehow. Because it's most out of character of me.But then again, it's also risky and there's got to be a huge trust bond going on for it to even be considered.
Anyway, lots of thoughts rattling around my mind.I know how important communication is,especially to those you hold close to you. It's all well and good being open and honest with strangers, but what does it really matter to them? If you want them to remain strangers of course. It is difficult though, especially when it appears so out of the blue.When really it's been playing on my mind for, well years. Is it something I will be able to continue to hide for another few years?Because in my heart of hearts I'm not it is.And having given in to lust in the past when I never thought it was possible for me to do,I wouldn't be surprised if I was tempted once more.Which isn't at all fair. And if I have a bit of foresight here,I should really do something about it, shouldn't I? Maybe that should be one of my new resolutions. To try and be more open about my sexual thoughts and try and communicate these thoughts better...