If you lost interest in the game, what did you do to develop interest in it again?

I felt kind of bored with live mode, so I decided to get into building up my neighborhoods. I've realized I love making restaurants, and spent about a whole day on each. I made a retro diner, a Chinese restaurant and a fine-dining penthouse restaurant so far. I also, for the first time, bought a restaurant and tried running it - and was amazed at how much fun I was having. For some reason I never played the running a business aspect of the game. So my suggestion is to try some aspect of the game you haven't touched and see if it's fun.