Rite of passage 

A rite of passage is a ritual that marks a change in a person's social or sexual status. The term was popularised by the French ethnographer Arnold van Gennep (1873-1957), in the early part of the twentieth century.

1. Its important to see Black Sabbath at least once in a lifetime, if you can. Its a rite of passage.
2. A rite of passage can be a religious experience

Rite of passage by IRON MAN January 27, 2005

Rite of Passage 

An activity someone older than you says will make you more mature, commonly idiotic, tedious, and/or destrictive.

"It's a rite of passage!" Shouted Uncle Mike, as I stared at the glass of motor oil and drain cleaner in front of me.

Rite of Passage by Delicious Taffy January 30, 2016