Top 3

Sooooo..... you know how you have sex with someone and be like "Oh, definitely top 3?" In conversation with one of my friends this weekend, it came up: what is top 3 exactly? Like..... what if you dealt with someone for a long time and in the beginning they were everything, but over time they got lazy? What if over time it just wasn't what it used to be? Does it take away from what they were? Are they still top 3? I mean..... are they still top 3 because they gave you some of the best sex of your life - AT SOME TIME? Or does their inability to hold that up knock them out? Let's realize also that over time, your memory of a situation may not be as good as it once was so.... I need some help here, because you can't have 8 people in your top 3, so how do you decide? I have to think about this...