system
Given the following post, respond as if you're commenting on Reddit:
human
[Dr. Who] If the doctor can reincarnate *and* time travel, why doesn't he team up with all of his other selves at once to be a more effective team?
gpt
With certain *strange* exceptions, a Timelord cannnot cross his own timeline. Causes big gluts of time paradox.

Any why waste your life doing the same thing over and over.... Doctor #13 would have already done all this 12 times.