Okay- honest truth. Because sometimes I need to hear it.
Forgetting your birthday is not okay. If he cared about you, he wouldn't forget about it. And even if he did that day, he'd at least write back to your text about hockey and maybe mentioned a belated wish. I'm not saying he isn't your soulmate and doesn't love you, but this should be a sign to you (as you are aware), that maybe it is time to let go. You deserve someone who will remember your birthday and share that with you.
I understand you are hurt, disappointed and angry. I would be too! And my birthday is right around the corner, so I may not hear from my ex. However, keep in mind, you can be mad, but not necessarily at him. Unfortunately, he isn't with you so doesn't owe it to you to say Happy Birthday. Please understand, I'm not being harsh, but it's something to think about (my friend pointed this out to me a few weeks ago about something I really wanted to hear from my ex and didn't). Obviously, if/when he reaches out to you, you can be cold, but you can be cold because you are angry he forgot, or you can be cold because you are letting go and it really doesn't matter. Or you can be nonchalent and not let this be the center of your life because you do deserve to be happy, you do deserve to be wished a happy birthday, and you do deserve better than what this is. We all do as a matter of a fact. I think we should be given an award for loving someone so much after all the shit they have put us through.
Green, I write this because it's almost therapeutic for me. I know all of this stuff deep down about MY ex and I think it's sometimes important to hear (or for me to write out). I want to believe that all things happen for a reason but I also want to believe that my ex and I are meant to be together because why else would I be so anchored to him and our love. Choose the path for you.