Forty years here, also.
Two things: Number one is that ecigs taste WAY better than tobacco, so if at teen tries the ecig first, the reaction to the tobacco will be “Yuck.”
Number two is that you don’t get the intense cravings with ecigs that you have with tobacco, so they’re not nearly as addictive. For many of these new vapers it’ll never turn into a daily habit.
40 some years for me, too. I haven’t had a cig. in three years and enjoy my e-cigs.