The gossip part, telling others now to date you because you are emotionally needy, is horrible.

I think contacting an old ex from high school for someone who is married with children is per se very typical behavior. Social media and internet have made these old exes infinitely findable, something that did not exist 35 years ago. And the draw to find out how those exes are doing now is hard to resist, whether one is single, happily married, or unhappily married, or anything in-between. So that curiosity by itself is not a show of disrespect for you and approaching Christmas as a general cue for connection is plausible, too. If one wants to connect, having a superficial reason to do so (to wish one a Merry Christmas) makes it a little easier.

He should have sent a message to accompany the friends request for sure. Facebook, unlike LinkedIn, does not have the functionality to embed a message inside a connections request, but he could have simply messaged you saying that he was thinking of you, regretted how he had treated you, and wished you a Merry Christmas. To that message he could have added that he would appreciated being Facebook friends.

That he did not address the points you had made in your Facebook message to him does not mean that he ignored them. He may well realize that they make perfect sense, but he does not know how to respond and how to address them and he may not have enough prowess in difficult conversations to know what to do. So he thought that he could get away with pretending that he did not notice your points. I know you see him as arrogant and you of course know him very well and most likely are right, but it also could be that he is simply unskilled and not particularly smart.

How many Facebook friends do you have? I get random friends requests and I usually accept them without considering them rude. There have been a couple of cases when women who are local service providers (hairdressers, "life coaches" etc.) sent me requests and I accepted without realizing that they were trying to expand their client base. If they are not aggressive, I do not unfriend. If they send me promotional offers, I unfriend. But I have more than 2.5K Facebook contacts so I do not particularly care, a few more or a few fewer. I consider them contacts, the word "friend" on Facebook is too ambitious. If you have a small circle of Facebook friends and they are all your real friends, of course I understand that you would be choosey about whom to accept into that circle. I just wanted to offer a perspective from someone who does not see friends requests unaccompanied by a message as rude.

I can give you an example: a member of my youth group sent me a friends request unaccompanied by a message and I was overjoyed. We live on different continents and I last saw him in 1986. I now follow him on Facebook and he follows me. He has a young son (he must have gotten married late in life) who sings in a famous children's choir and he posts videos from the performances and I always watch; they are utterly amazing. If I go back, I will be sure to see him. But he did not do anything bad to me in the past. We were on perfectly good terms, although not very close. So I think the real reason behind your indignation is not the friends request out of the blue, but the past unresolved hurt for which your high school ex never apologized.

(Just to acknowledge that in general, yes, of course, you are right, attaching a message when wanting to connect is better. When I send LinkedIn connection requests to people who are not my colleagues and whom I do not personally know, I customize the message so that the requests do not come out of the blue. Say, I mention that I was at a web conference, they were presenters and I was impressed and now want to connect. When I connect with colleagues, I omit that extra step.)

At this moment I wonder if you would benefit from his apology. If the answer is yes, then your response to him was too blunt. You also told him that there was no reason for him to reach out to you, but does not he know better whether he has a reason or not? You can decline and are well within your right to decline given the outrageous past mistreatment by him, but you are not to tell him whether he has reason to contact you because that it about his frame of mind which he knows better than you do.

You can write to him now that you might reconsider his request if he is willing to reflect on his behavior in long past and offer a genuine apology. Offer him an olive branch and see what his reaction is. Say it coolly, just to give him a slight chance. If he needs an explanation, you can offer a hypothetical in which the tables were turned, you were the most popular girl in high school, you knew everyone, you told everyone that he was emotionally needy and not to date him... how would he react? He might have never been thoughtful, might have never considered another's feelings... you can give him a chance. It can be done without making him win and without losing your sense that you took the high road. That, of course, if you see value in having him see that he hurt you and apologize for that.

I do not want to detract from you feeling proud of how you handled it, but believe that you exhibited the bluntness that you recently wrote about when you called yourself an external processor. And your theories are simplistic. For instance, you surmise that he might be having marriage problems and find you an easy to reach online distraction. But a popular football player who knew everyone in high school has many more available online and offline distractions–he does not need to reach for you. People usually do not change that much: if he was popular back then, he probably is popular now. There must be many women he can reach out to very easily, without taking chances that an ex-girlfriend whom he mistreated 35 years ago might not respond or respond angrily.

He might simply be suddenly nostalgic, not about you per se but about his youth which you might personify for him on some level. And the approaching New Year when people think about where they are in life and are keenly aware of the passage of time might cause him to be nostalgic. At least it seems likelier to me than the "marriage difficulties" hypothesis.

I hope you do not mind my offering alternative theories. If you want to craft a message to him that would be cool but would give him a chance to reflect and apologize and show you respect, I think as a community here we can do a good job.