||I've only heard the "let's be friends" line twice, and both times it was from a guy who I had quit talking to months/over a year before, trying to come back and re-establish a friendship after much time had passed. * I personally don't like it, either when I have ended a relationship or the other person has.
I don't understand why on earth I am supposed to want to be casual friends with someone who I will inevitably have to hear about their new relationships. And why would I want to share the details of mine with them? If I found myself to be incompatible with someone after all, there's no reason to spend time together (I don't like being around them any more), and if I'm still attracted to the person then there's no reason why I'd hang around after the relationship had ended. Unless, of course, the point is to just make me feel like crap all the time remembering how much I liked someone and can't have them any more. The "let's just be friends" thing has always mystified me as not making any sense. Hanging out with ex's is uncomfortable and awkward at the very least.
I can only think of two possible explanations for it, both of which have already been mentioned: either the party saying "let's just be friends," is really saying "I want to try this other person(s) out, but I want to keep you around just in case," or else they're trying to soften the blow, and really have no intention of returning any of your phone calls anymore. As in, "let's be friends," and you go out for coffee twice a month, then once a month, then after a few weeks you're simply forgotten.
I'm not on speaking terms with anyone I've dated/had a relationship with/been attracted to in the past, besides my current boyfriend (obviously). I *usually* don't even keep photos or letters after the fact, so I certainly don't see why I'd want to hang around with them in person. I don't think I'm intentionally cruel that way, it's just my way of dealing with things, and it prevents that kind of back-and-forth melodrama of people who break up several times a year and are constantly getting back together. (My body can't handle stress like that.) I'm not even on speaking terms with any of the people I was friends with in high school (bad memories). I'm a very loving, accommodating, patient, generous, understanding and forgiving girlfriend (among other things ;), but if you ever say it's over, you have a very small amount of time to change your mind, and then that's it. I get extremely upset; I treat my close friends and SO very well, so when that trust is betrayed or it no longer means anything to someone I really don't want to be reminded of it at all or have anything to do with them. (Out of sight, out of mind...)
* A fellow in Austin (a 25 y.o. professional magician, rabbit-in-the-hat kind, not a Wiccan) whom I dated for about two-threeish months decided to "let me go" by taking me to an IHOP and telling me "You know you're never going to see me again, right?" His excuse for why he was no longer interested in seeing me was that some magicians in Romania had invited him to go live there in this castle and practice magic, and/or he was moving to Colorado for an unspecified length of time. I went back to Houston from Austin and did not speak to him for over a year, until one night when he contacted me over the internet and said "I didn't mean I never wanted to talk to you again." WTF? Then he said he was sorry he let me leave Texas. WTF again?! (I was out of state at the time.) Then he mentions his cat (he didn't have a cat when I saw him!) and the girlfriend he has living with him IN HIS APARTMENT IN AUSTIN. Hmmm...says I. I questioned him long enough to try and figure out what his motives were, after he apologized a couple of dozen times I told him not to bother me again. He's sent me a couple of e-mails since then, and I finally had to write him an extremely nasty letter before he got the point that I didn't want to talk to him. Ever. Again. Heh. And that's why I hate Austin, boys and girls. ;) True story!
"Ars longa, vita brevis...Art is long, life is short."