I don't go to confession only if I have committed a mortal sin, but I have committed mortal sins that were not of a sexual nature.  Since sexual sin hadn't been my main struggle growing up, I didn't concern myself as much with it until I was in romantic relationships.   I do disagree with you on it being an adult sacrament though.  I knew times where I fully acted in a way knowing that I was doing wrong, even as a child, and the very act of confession, though affectively mundane, was always a chance at renewal.   One encounters mercy in a good confession, which is why our Pope frequently encourages going to it, and any child should grow up exposed to mercy. And look how much we sucky souls need it today.  While it isn't *necessary* to confess for venial sins, there are graces that flow from it anyway.   My parents didn't demand it of me but they regularly went and I would be the one to ask for a ride when I needed to go.