"Yeah, but like Christian atheist?"
People have actually said that? WOW!!!
From what you've said, I can state that you're among the luckier ones, that had gotten over the god problem pretty early, and that had support from someone close (your mother).
There is less fire and rebellion to becoming an atheist, which can be a bit dull, but perhaps it is making it more accessible for those who are losing their faith.
When I finally realised that I can't believe in (a) god anymore, it didn't felt like I was doing something rebellious at all. It was very normal and right, and it felt like I was supposed to do that a long time ago. The main feeling was relief. So I guess you're right, it is a bit dull, especially after a while. But that doesn't mean it's necessarily a bad thing. It slowly becomes something normal, natural, just another part of you.
From a similarly zero religiosity background, frankly the only change I have experienced myself is the entry of my atheism into the political sphere.
-I used to think religion could be a personal affair, I now see that as false.
-I used to abide by the mantra "freedom of religion" and now feel that's an oxymoron.