Barney: I brought you a present. Recognize this?
Ted: It's my building.
Future Ted: [v.o.] Kids, you may remember that, a few years earlier, I was chosen to design the new Manhattan headquarters for Goliath National Bank. It was the opportunity every architect dreams about. And when the project was ultimately scrapped... it broke my heart.
Barney: Do you remember how awesome it was to be co-workers... Nay, bro-workers?
Ted: Wait a minute. Y-You don't mean...
Barney: Ted Mosby, it's back on. We're gonna build your building.