Robin: Okay, so we agree? This goes back to Lily wanting to camp out for a wedding dress?
Ted: No. Wait. It goes back further. Remember why we were eating hot dogs on the East Side?
[flashback to Ted riding the subway:]
Ted: 1939?! This penny's from 1939!
[cut to Ted and Robin at MacLaren's:]
Ted: A 67-year-old penny. Do you realize this penny was minted during World War II?
Robin: Oh, so was my grandfather, but that doesn't make him interesting.
Ted: Look, I know a little something about coins, and this baby is worth something to a collector.
Robin: No, it's not.
Ted: Yes, it is! You know what? I'm gonna take you out to dinner with the money I get for this little guy.
Future Ted: [v.o.] And that's exactly what I did.
[cut to Ted and Robin eating while walking down the street:]
Robin: You're lucky there's still a place that serves anything for a dollar fifty.
Ted: Hey, that's 150 times its original value. Actually, the meal was only $1.49. [looks at penny] 1984.
Robin: Hey, in 50 years, we can get dinner again.