Projects used to be 'things I want to do with a clear goal in mind'. But in recent months I've realized that goals are dumb, and that I am better off (both in terms of happiness and in terms of results) by thinking of projects as things I'm working systematically on to improve, explore and to learn. Paraphrasing Scott Adams:

Goals are for losers. Literally - if you have a goal, you are a loser until you may or may not succeed. Goal oriented people are fighting discouragement at every turn, while systems people are winning every time they successfully apply their system: every time they succeed at what they set out to do. Losing pounds is a goal, but eating right is a system. "A system is something you do on a regular basis to increase your odds of happiness in the long run." It is only a system if it works more often than not - buying lottery tickets is not a system.