There is a girl I got to know 2 years ago and we are chatting daily back then.
When we both had to prepare for finals in university, our conversations were put on ice. After I graduated I got really busy with my business so we hadn't spoken for a long time.

Now, maybe once every 3 months, she asks me how I am doing, how work is going etc.
I only get back to her with short answers, since I learned on TRP that girls crave for something they can't get. I do that, because I was a really needy guy back then, used to answer her in matter of seconds, since she was the only girl I chatted with. I basically got friend zoned and now I try to get out of this and it seems like it works out.

Yesterday I sincerely congratulated her on her birthday to create a push-and-pull-game.
Today she finally asked me why I only write short answers, especially because that used to be different. She'd like to know why I've treated her differently from now on, and whether there's something else behind it.

What is your suggestion? How should I respond?
Looking forward! Much love