1. To give me something to do while I'm waiting for a kid. I spend a lot of time at soccer practice, games, for our turn at the pediatrician or counselor.
2. To give me something to do during a meeting. My snarky answer for why I knit during meetings is, "So I have something to show for my time." Otherwise I'll be doodling or thinking or something. Stockinette socks are good for this.
3. As an exercise to figure out how to do something. I like the puzzle of how to get the thing in my head into a thing I can use. Sometimes it doesn't work. This is not usually portable knitting. But it is something I will work on at home while watching TV.
4. While I am keeping someone company. The youngest is at an age when she still needs a lot of company. One thing that I found while watching the Cold Spagetti Western a lot with my older daughter is knitting helps me put up with the repetition of watching the same show over and over.
5. Because we need something specific. Like a sweater for a little kid. Or a hat for a bald baby. I think I am a process knitter - I knit things for the exersize of knitting it and am not driven by needing the end result. So, unless the pattern I picked fits in one of the above categories (e.g. it is interesting or it is boring and small), it doesn't get finished quickly.
6. To feel like I'm doing something helpful. It's hard to volunteer my time at a place without finding baby sitting or time off from work. But I have time to knit a square or a hat or a pair of mittens. Hopefully they will be used, but I've gotten to the point where it's OK with me if they don't.
7. For a new baby. I like to knit at least a little hat for a new baby. They don't take too long and the cotton/elastic blend is useful and wearable here in Florida. If I have the time, a sweater or blanket is nice to make too.
Maybe I only have 7. shrug.