I guess you've never heard of positive affirmations? Athletes and coaches of athletes use them all the time. They have to visualize being the best athlete in the competition and verbally affirm it and BELIEVE it. Do you actually think Meryl & Charlie haven't said they are the best skaters in the world? NO Olympic level athlete could make it to be the best if they don't say it to themselves and BELIEVE it.
Generally, when we hear someone like Sylvester Stallone or Arnold Schwarzenegger openly say they are the best, or even Trump who says it all the time. We all just roll our eyes at their arrogance or belief in themselves.

But when a
woman says it, whether in jest or affirmation or really believing it, she's suddenly a ***** and full of herself.

I have to wonder if most of the dislike for her (from the general public,) after airing she said that she thinks she is the best dancer, is from that mentality. That if a woman says anything about herself, she should be humble or not say anything at all.