I don’t know if I should be feel some type of way?

My Bf has been writing a book since last year when we started dating and he published it this month, but didn’t tell me until just now. Like I’m proud of him for getting his book published but I just feel some type of negative way as to why he didn’t tell me about it.

I was just like..okay. This is random. I thought we were open enough to share about our goals with each other.

Idk maybe I’m over exaggerating. Would you feel some type of way?