Quote from Future Ted in Double Date
Barney: You will not believe who we saw tonight.
Marshall: Dude, um...
Barney: We saw the third doppelganger!
Future Ted: [v.o.] I should explain. Over the years we had spotted two strangers who looked exactly like members of our group.
[flashback to the group walking down the street:]
Barney: Hey, hey, hey, hey! [points to a short-haired woman wearing a flannel shirt and a baseball mitt]
Future Ted: [v.o.] Lesbian Robin.
[flashback to the group, minus Robin, outside a theater where they see an advertisement on a bus for a Mexican television show, "Senor Justicia":]
Future Ted: [v.o.] And Mustache Marshall. By the following summer, we would find the remaining two doppelgangers. But I'll get to that.