Didn't you also stop reading Discworld novels after you turned 14 because you had better things to be doing? If a book has a decent hook and good pacing, I don't let its target audience stop me from reading it. All I lose are a couple evenings I could've been bullshitting around in a Battlefield game or something.
<-- Also read Xanth novels until their number became too ridiculous.
<-- Also read Xanth novels until their number became too ridiculous.