MANDRAKE:
As with the OP, it’s all about what you knew. People also forget that what happens to us in our early childhood sticks with us.
I can relate to your mom because she was not raised a JW and when she left she just was able to resume her life before the Witness religion. That’s what I did as well. While celebrating birthdays isn’t a big deal for me and I can take it or leave it, I do like the holidays of Thanksgiving and Christmas because I associate them with happy times and non-JW relatives who were the only people who truly cared about me.. I am glad I realized this fact before it was too late 🕰 and that I was able to reconnect with everybody!
As ex-JWs it’s all about making yourself happy and comfortable navigating your way through the world and you can pick and choose what you want. You don’t necessarily have to get all interested in birthdays or holidays just because the religion forbade it. It’s perfectly okay. This would be like adopting a reckless lifestyle just because it’s directly opposite the values of the JWs and other religions.
Do what you are comfortable with.