It's weird, ain't it? All the ponds I've ever fished (mostly up north), were unmanaged and produced great fishing. No feeding, aeration or anything. Under the right circumstances, you don't need all that "fancy" stuff, but it does expedite the process. Think about this: Most public waters aren't managed like private ponds are, and can produce great fishing. With the right food chain and "happy water" as Mr. Lusk says, you can have an unmanaged pond be successful. Is it common? Probably not. You can buy 100 lottery tickets and lose on all of them, and the next person can buy just 1 and win the jackpot. It sounds like those ponds you found hit the jackpot.

"In the age of information, ignorance is a choice." - Donny Miller