Would you be able to reinsert your tooth back into your mouth after you've been knocked out?

Sometimes: If a tooth has been knowcked out it can be replaced into the socket. This has to be immediately or there is risk of it failing. It is important that you see a dentist asap about this to have it splinted in place for healilng. After 2 hours the chances of the tooth lasting is very low. Good luck.

Mostly YES: When a tooth is evulved [knocked out] what usually happens is the ligament that surrounds the tooth has been torn but is still alive. If the tooth is gently rinsed not scrubbed and placed back into the socket, and then stabilized, it can heal without complications.