Even when you know that you'll tend to prefer people who flatter you, it will still affect you.

Everyone would rather be surrounded by people who flatter them.

It's just for most people that's not an option–we have no choice but to be surrounded by many people who won't flatter us.

Which is good–that helps us learn our flaws and own them and grow.

But on the margin, if we could choose between one person who flatters us and one who doesn't, you'd always pick the flatterer, all else equal.

If you are hyper-successful, you'll have an endless array of people who would love to hang out with you.

That means the people who you allow to hang out with you will be structurally much more likely to pander to you.