My life-long consistent hobby has been learning new hobbies. Discovering how something works or finding new ways to do things is a high for me. I get interested in something, if I'm not careful, I fixate on it for a while, learn everything I can, add it to my mental toolbox, and move onto the next thing. 

After a few decades, I've racked up quite a list. I will not list something unless I could talk about it for at least 30 minutes unprompted.