Totally agree with kml on the birthday greeting. I don't see an issue with you sending her a greeting. Well, actually I do, as in I would NOT do it, but I'm not you, so I get that is who you are and you feel like you are staying true to yourself and being classy, so I get it. BUT, you should TOTALLY leave out all the mushy stuff. You can still be classy and stay true to yourself through the break up with a simple "happy birthday, hope you have a wonderful day" or something along those lines. Polite, friendly, but not sappy, mushy, romantic, lovey/dovey.
To Don's point, I agree that you are worth a lot more than what you got. Don't get me wrong, I'm sure B is a lovely woman in her own right, but I do not think that she is the right woman for you. You are so much more valuable than you give yourself credit for (like G) and you need to learn that REAL value. I, like Don, suspect that while you say you are moving forward and letting it go and all of that, if B showed up at your door tomorrow, you would welcome her back with open arms. Now, if you did that, I couldn't really say much beyond you do you, but as someone else pointed out in an early comment (I think it was Juju), if one read between the lines of some of your last posts right before you and B broke up, you were not as happy as you wanted us to believe. I think you had doubts, but like G, you were trying to out think them or put them to the side or making excuses or whatever you want to call it.
To kml's recent point above, I think that she's right that settling vs. finding the ideal mate really has a truth somewhere in the middle. Nobody is perfect. NOBODY. But, you can be familiar with the things that are most important to you and choose a woman accordingly. You have pointed out yourself, Andrew, that there were several seemingly important layers that you and B were incompatible on: intelligence level, financial acumen, general interests. Differences can be a good thing because they allow 2 people to maintain their own individual identity in a relationship, but too many differences is just too hard to balance. You need to find someone with whom you are more compatible and I think in the grand scheme of things, you and B simply weren't compatible. As much as I hate to say it, because I was SO anti CL all along, you need a woman more like her: educated, professional, earns her own money. Someone who is a saver and doesn't live paycheck to paycheck.
Sure, maintain a friendship with B, if you choose to do so (though I am probably in the minority when I say that I just never really see the point in that. I have one X from my past that I am friendly with and we talk every few months, just catching up, but everyone else is fairly non-existent in my life because I outgrew them, if that makes sense). Anyway, by all means, keep it classy and friendly, but don't let her think that you are still just sitting there waiting for her to run back to you. That isn't healthy for either of you.
Me 50, H51 3 adult daughters from XH's first marriage (plus 4 grandkids) Divorce final 12/17/2014 Marriage #2 12/31/2019 1 adult daughter and bonus daughter-in-law from current H's first marriage