In life we all learn what you can & cannot do, or in this case what feels great & what doesn't, through trial-and-error. If you buy this book, it will be an ERROR. While it may look cool to have it lying around for people to "accidentally" see, an experienced person is probably going to laugh. I'm sorry, but this book is for the younger person who just wants to see how many ways a body part (especially the male's) can bend or TRY to extend. Most of the positions are just repeats drawn from a different angle. Some ARE impossible unless you never want your man to use his "item" again because you helped him break it backwards. Most are just positions...not meant to feel great or even good...just that you can do them but they're not meant for much of anything. I think Cosmo used their name to sell a book...just a book with not much "oomph". My honest advice, coming from older adult experience, save your money and just let nature, & what feels great to you both, take its course. You don't need a book to tell you what should feel good to him (or her). Instead, try just asking the person. I've found that communication is the way to a GREAT sex life! Both of you need to find out what feels great to each other and invent your own various positions from there....