If you think that there's nothing better than being you, then you're full of egotism, a word for an inflated sense of self-importance.
Most people believe it's good to have positive feelings about yourself and healthy self-esteem. But some people feel a little too good about themselves, and that's called egotism. People suffering from egotism think the world revolves around them. They're arrogant, cocky, overconfident, selfish, and generally think they're better than other people. And having an ego of that size is generally not a good thing.