I'm sorry if I'm just not in on the joke, but I can't believe people here are giving you such bad advice. No, you should not back up your computer in general or before upgrading to a new operating system.
This is a thought provoking question which probably can't be answered in a single post (perhaps we should start a series about the topic?).
I've also wondered about backing up my computer and if it makes sense to do so. I wonder about a lot of things, here are some examples:
- I went to a car forum and asked if I should put on a seatbelt before driving.
- I asked my doctor if I should wear a helmet on my motorcycle.
- I went to a skydiving forum and asked if I should pack an emergency parachute before jumping.
- I called an electrician and asked if I should turn off the power before working on my house wiring.
See, you and me are just curious minds - yet we don't like to actually think. Or perhaps, we just Think Different
I'm reminded of one of my favorite quotations:
You see things; and you say, 'Why?' But I dream things that never were; and I say, "Why not?"
I dream of backups that never were, and say "why not...why did I not make a backup?"
In conclusion: very good question, I think the debate is out on this backup situation, no one really has a definitive answer.
But I say don't ever do it; it will be a good lesson for what happens when you don't.