Simone Biles says she will always "cherish this unique Olympic experience" despite her time in Tokyo being derailed by a psychological condition known as 'the twisties'.
Biles withdrew during last week's team competition, suffering from an inability to orientate herself in mid-air.
She subsequently pulled out of the all-around final, and the first three apparatus finals, returning to claim bronze in Tuesday's closing beam.
With team silver Biles leaves Japan with two minor medals, a far cry from the four golds and bronze from Rio five years ago.
"Not at all how I imagined or dreamed my second Olympics would go but blessed to represent the USA," she said in a post on Instagram.
"I'll forever cherish this unique olympic experience. Thanks everyone for the endless love and support.
"I'm truly grateful - leaving Tokyo with 2 more Olympic medals to add to my collection isn't too shabby! 7 time Olympic medalist."
The 24-year-old's pursuit of five gold medals to equal the women's record of nine was all but ended when she baulked in mid-air on her opening vault in the team competition, as the 'twisties' struck.
The disconnect between brain and body, with the consequent loss of spatial awareness, is a potentially lethal cocktail for a gymnast somersaulting at high velocity off a vault backwards.
Reflecting on her comeback heroics behind Chinese duo Guan Chenchen and Tang Xijing, Biles told NBC: "(The bronze) means more than all the golds because I've been through so much the last five years and the last week while I've even been here.
"It was just... It was very emotional," she said. And I'm just proud of myself and all of these girls as well."
She added: "I didn't really care about the outcome. I was so happy that I made the routine and then I got to compete one more time."
Social media was alight with heartfelt congratulations.
"Congratulations @Simone_Biles... the most important medal @Tokyo2020 @Olympics" tweeted Nadia Comaneci, who entered Olympic folklore at the 1976 Montreal Games with a 'Perfect 10' score.
"Not enough words to express how proud I am of you Simone!!!" coach Cecile Landi posted.