Over the years your perspective on how long sex should last has probably changed. In addition to the knowledge that you have about your body and sex. One of the perspective that make the first big difference is age. When we are young “All genders think this is how it’s supposed to be. Guys think they should have a huge penis that will last for an outrageously long time in bed. And everyone thinks that when the penis enters the vagina, it's shared pleasure and fireworks for all parties,” says Finnish psychologist and sexual therapist Patrick Jern