If you went to Junior High or High School in America in the mid-1980's, then this was one of the quintessential last-dance songs. Sometime around 10:50 or 10:55 you'd sidle up to the girl you have a crush on and hope and pray that when "Last Dance!" was called out you'd be close enough to grab her or (jesus, if this would happen you would just die) she would grab you and you'd dance and then maybe walk out together down to Denny's and drink coffee and have conversations far too serious for teenagers.
Anyhow, the great thing about "Forever Young" is that it works well as a slow dance and a fast dance (as opposed to something like "Don't You (Forget About Me)" (Simple Minds), another last dance song, which is only fast dancible). So, if the girl wanted to, you could slow dance, but if she didn't, then that was okay too.