When I was a kid my favourite television show was "lost in space." It was about a family who explored other worlds and became lost in space. They travelled from planet to planet, encountering monsters of all kinds. I still remember the characters including the robot who was smarter than everyone in the show. That was several years back...but why do I remember all that? Because its etched on my brain.
We were created with brains that are made to lock information in permanently. That's a good thing ofcourse. Unfortunately, when we make decisions to put bad information into our brains, that's locked in permanently too. Whether its something we see on TV or read in books or something we hear, its liable to gone rushing back into our memory when we least want it there.
The best solution is to make good choices about what we put into our brains not because someone told us we should, but because you want to keep off from sin for your own happiness.
There will always be times when we have the opportunity to put something into our brains , when no one is looking,and not our parents, teachers or even partners will ever find out, but is it adding any positive value to your life? Always put in good stuff and you'll get the best results from that wonderful piece of equipment God put in your head.