Bull****. All that matters is how much you've read, not your age- at least, once you get into the double digits. I was reading great 400-page bricks at age 12, and appreciating them almost as well as I do now- fact, it was probably more advanced stuff than I generally read now. Most little kids are too busy making mud pies, playing little league baseball (talk about a waste of time), or staring at the TV for hours on end to actually read- me, I went the way of myopia, and I can't even say I did so as much as many kids could or should.
Never read a Tom Clancy book, never will. I allot myself enough intellectual snobbishness for that. King's books... don't you think they're a bit, say, gimmicky? I mean, you've got an evil clown that turns into some freaky thing into a giant spider! Ooh! Ahh! Aliens from outer space that make people evil! Booga booga! He's a halfway decent writer (a rare thing on the bestseller rack), but most of his stuff is kinda kiddie and didn't scare me in the least.
Try Kingsolver. Or Vonnegut. Or Sartre. All light reads (pretty much), all fantastic writers.