I'm 30- and I always start with the data first as well. Linus said good programmers always think data first, and that resonated a lot with me when I first started coding. As I got further along, I realized how true it was that application logic often follows the data model.

Treating data as an afterthought is a great way to have to be re-defining your application logic every time you re-define your data because you forgot something.