system
Given the following post, respond as if you're commenting on Reddit:
human
[Doctor Who] Is there an in-lore reason the (current) Doctor rarely meets with his future self?

Whenever there’s a big crossover event with multiple incarnations of the Doctor meeting, it’s almost always the current Doctor and whoever came before him. There is only exception I can remember, and that’s when Peter Capaldi appeared briefly before his official introduction. Even there, a moment where every Doctor to have been in the show at the time (1-12 + John Hurt) appeared, Capaldi’s Doctor proclaimed that “All Thirteen” were there. 

That line suggests that The Doctor doesn’t recognize whoever he will become as existing yet, despite the fact many past Doctors have met their future selves. 

Of course, in real life, they just hadn’t cast Jodie Whittaker or anybody else, there were only 13 Doctors at the time. But that’s no fun, so is there any reason that, in lore, no future Doctors interact with the current Doctor?
gpt
The current Doctor doesn't know where they will be, but the future Doctor knows where they *were* and avoids it, since paradoxes are bad news.

That's why when Doctors meet each other, it's usually because of some crisis bringing them together without them having a say in the matter. 

The TARDIS may go out of its way to prevent this from happening too, which is why it doesn't usually happen even when the Doctor is traveling more or less randomly. The TARDIS doesn't like things that are "wrong", like Jack, so if it senses that the Doctor (and itself) are already somewhere, it changes course. That could explain some of the times it misses the mark.

And of course time and space are vast, so even a long lived person like the Doctor has plenty of places they've never been.