I had bad experiences with credit in my early 20's. Not ashamed to admit it. The more I got to learning about how the credit system works the more I was boggled at how bad it really was and was bound and determined to get out of it by my 30's. So I spent a lot of time in my mid and late 20's with a start up that I eventually sold for a fair amount of money. It wasn't millions, but enough to pay off my debts, buy a condo that I rehabbed and then got luck to flip for a good profit, and then I bought the farm next to my Dad's.
Now I pay cash for everything. If I need a car, I try to find a good used one (although thanks to cash for clunkers there aren't a lot out there. My 2004 Chevy Impala with 130k miles could fetch way more than it's worth at the moment).
After buying the farm, I didn't have enough to buy another place so I decided to rent a loft. Walked in and they all their "credit" requirements. I asked them to figure out the amount of the lease and I'd go right to the bank and get a cashiers check for the full amount up front. Amazing how they no longer needed to run my credit.
Last year I created an LLC for my part time business of going to estate sales and then dealing in antique and vintage furniture. Went to see about credit card processing from the bank and a couple days later got a call back stating that they had a problem: there wasn't any credit records for me. I smiled, said don't worry about it and opened a square account.