When I was a kid, I answered 1...e5 to 1.e4 because my dad told me (or maybe I imagine he told me) that it was the best answer. After I got my first openings book (Walter Korn's Modern Chess Openings), I tried the Alekhine Defence for a while, because it seemed solid and did not have pages and pages of theory. As an adult, I tried the Caro-Kann, and currently the Sicilian Sveshnikov (no doubt influenced by Kramnik, Leko, etc.).
As white, as a kid I started out with the Scotch and gave it up after one silly loss (sad & foolish but true). Tried the Ruy Lopez, too much theory. Tried the King's Gambit. Finally settled on the Two Knights/Evans Gambit, since I don't play against GMs, and don't need bulletproof openings.
In response to 1.d4, it was an adventure involving the Queen's Indian, the Benoni (for a very long time), the KID, and finally the QGD (Tartakower).
Bottom line is: if you plan to play chess for maaaaaany years, you can expect your repertoire to change. You may even want to revisit openings you gave up for some reason. Anyway, someone said (I keep forgetting who) "know thyself", and since the "self" changes over the years, learning is an ongoing process.
How did you choose the openings to study which you have since stuck with, to the exclusion of others? Why have you foresaken some openings? How does someone who knows only one opening go about selecting a new opening to master?