First, my hat comes off to the other people with far too much exposure to "Hitchhiker's...", I salute you.
OT: The meaning of life is to live it. Even if your choice or circumstance is to sit on the couch all day licking the Frito crumbs from the corner of your mouth, there is meaning in that. The question is how much do you want your life to be worth to you? The day you die, you stop caring about what anyone else thought, about that time you looked like a total jackass, about those opportunities missed. The question is, right here and right now, is that all you want? Self pity?
If you're happy with that, then you really don't need anything else. The meaning to life is finding the motivation to pursue your own happiness, and to pursue it despite the fact that there are people and circumstances out there whose own purpose is to stop you.
"It's not about how many times you got knocked down, it's how many times you got back up"