Twenty-two Olympic medals is really just the beginning.
First of all, he started swimming at the tender age of 7.
The first stroke he learned was backstroke because he was reportedly afraid to put his head underwater.
And three years later he set a national record for his age group in the 100m fly.
His time was 1:08.54.
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In 2000 he became the youngest American male swimmer to compete in the Olympics in almost 70 years.
He was just 15 when he competed in the Summer Olympics in Sydney.
Mark Baker / Reuters