[flashback to Ted, Barney and Marshall on the roof with a small inflatable pool:]
Ted: Marshall, lately it takes you two tries to get off the sofa. You can't jump that far.
Marshall: Oh, really?
Ted: Really.
Marshall: Watch me.
Future Ted: But he didn't jump.
[three hours later, Barney and Ted are in the small inflatable pool while Marshall still teeters on the edge of the roof:]
Barney: This actually is kind of nice.
Ted: Right? Right?
Future Ted: [v.o.] And in the years that followed, he kept almost jumping. But each time, without fail... He didn't jump.