I think it’s a “had to be there” kind of thing. A bais yaakov high school, and definately overnight camps, produce a deep feeling of achdus and belonging. (usually)
Yes, there ARE many songs, productions and plays, all of which get many/all involved. So the songs and tha music stay with us, in our hearts (not to be too mushy), as a true Jewish song should. (“A Jewish song of any kind is only precious – if and when – it brings us closer to Hashem” – Abie Rotenberg). But a bigger reason, i think, is that the songs take us back to those teenage years of fun, friends and companionship; the memories are linked with the tunes. So sing and enjoy! (even 20 years later!)