All first experience is formative experience. The age it occurs is irrelevant except that you may appreciate it more because it didn't get handed to you on a silver platter or spoon fed to you.

You take two kids the same age. One starts learning to read at age 6 and the other at age 16. It takes 72 hours of instruction, on average, plus practice time to learn to read. At 18, you still have two 18 year olds who can read.

You could say that the one who started reading at 6 is more practiced, but that's no guarantee. You're just as likely to have killed any desire to read in that kid by forcing him into it or making him read stuff he doesn't like. Also, he's still going to be restricted to the comprehension he's capable of at whatever age he's at.

You're putting too much emphasis on "formative experience". Sexuality and relationships don't need a benchmark or a time table. That's not healthy thinking.