Self-confidence boosts when I see another girl not so pretty?

I think the answer is obvious here but i feel i have to ask to find out truly. Why when i see another girl that's not so pretty (not specifically ugly/hideous) based from my own objective view, my self-confidence increases? Does this happen to other girls too, having their self-confidence boosted when they see another girl? i know this question may sound silly lol

Self-confidence boosts when I see another girl not so pretty?
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