Did I have to be in the Holocost to have an opinion about it? Of course not? Or in Korea or Vietnam for that matter? I don't think so.
Usually I've found when the opinion giver's advice is summed up by the phrase, "Been there, done that," there is a great lesson to be learned---not necessarily from their experiences, but volumes can be learned about that person's cynicism and negativity. THAT can indeed be useful.
Hey, be as opinionated as hell....99% of the people on the planet already are! But also don't forget to have an inquiring mind, and reserve the right to change it from time to time. Some things I felt strongly about at age 19, I really don't give the "derriere of el rato" today. cheers, from Hardiman