Future Ted: [v.o.] Kids, your Uncle Marshall definitely doesn't want you to know this, but he also smoked off and on. It all started when he was 13, on a camping trip in Minnesota.
[flashback to a young Marshall in a snow-covered forest in 1991:]
Ricky: Come on, Marshall, let's celebrate. It's summer vacation.
Marshall: Okay, but just one. This is my first and last cigarette ever.
Future Ted: [v.o.] And that was the first of many, many last cigarettes ever.