As FrugalZen said, the MG MGB was a British sports car notable mainly for the fact that it required constant maintenance to keep it running.  (Not recognizing it makes you sound young, not old.  Surely anybody over 45 would know an MGB, wouldn't they?)

I agree that the retire-early-and-often lifestyle is a lot more appealing to the young than to people who want to, for example, support a family.  But many people reach their thirties with no savings despite having spent a decade working full-time at a regular job.  This strategy lets you reach your thirties with modest capital and having been able to spend a good fraction of your time doing exactly what you want.

I wrote a post on calculating your "number" called How much do I need to retire, how much can I spend.  It's the way I always thought about it.  But I think I might have been happier if I'd been less focused on retiring early and more focused on doing cool stuff when I was in my twenties.

I've also got a review of Tim Ferriss's 4-Hour Workweek.  Yes, his insight that you can set up a small business that continues to spin off money without you having to put time into it day after day is brilliant.