Talking about sex during your formative years can be incredibly awkward -- even squirm-inducing. But whether you experience formal sex ed, awkward "birds and the bees" talks, candid conversations with friends or all or none of the above, it's all theoretical until you're actually doing it -- which can make for some surprises along the way. On a Nov. 7 Reddit thread, commenters answered the question "what is something about sex that you wish someone had told you?" The thoughtful responses touched...