Stop texting your exes on their birthdays. It just shows how honestly selfish you might be at times.
On a day such as your birthday, the last thing you want to do is get upset from getting a text from your ex, when you're already reminiscing about how this year was different than ones in the past.
If you aren't going to message or text your ex any other time of the year, why do it on their birthday or holidays? Obviously these events have past memories with them, but to say your emotions matter more than another's is probably related to a big personality flaw.
This happens literally every year to pretty much everyone and I'll never understand how one could think it's appropriate.
The day's not about you. Stop it.
Birthdays are the one day a year we get to be selfish and have nothing but a fun time!
"I guess I'll just get drunk and then get upset later about our crappy past." Kinda seems like that's what you wanted by sending that unnecessary text in the first place.