The Flash: 24 WTF Moments
19. Barry Loses His Powers... And A Tooth
After our Barry demonstrates his powers to a fascinated Young Barry, he realises that this happens to be the very day that he received his abilities after being struck by lightning and covered in chemicals while working in Central City Police Department's forensics lab.
Fearing that this version of Barry won't become The Flash, he sneaks him into his place of work and attempts to recreate the very same incident.
However, this leads to both Barrys being struck by lightning, causing Prime Barry to lose his abilities while Young Barry gains them.
And because that's not enough, Prime Barry also loses one of his teeth, which he ends up supergluing back into his gum - and to the glue's credit, the tooth stays stuck there for almost the entire remainder of the movie.