8. You Might End Up In Therapy
You never know who you will bump into when you travel back in time and as poor old Marty McFly discovered, there is a chance that you might meet your mum and she might try and get in your pants, causing you to have to stay in therapy for the rest of your life. Quite frankly if there is event a remote chance that you might accidentally nail a relative then I would rather not risk the whole thing. People in certain parts of Norfolk might find this an intriguing proposition, but the rest of us would probably rather avoid somehow becoming your own dad.