What's a fun hobby that's easy to get into?

My ex and I broke up last week after she expressed her desire to sign up for a foreign marriage agency. Now, I just want to focus on moving on and forgetting all about her. I was thinking of taking up a new hobby, but I'm not quite sure what the best one would be. Any suggestions for hobbies that are fun, but easy to get into? I want to do something entertaining and productive with my spare time to keep from thinking about her.