The best way to put it is.
You’ve been eating only one type of hamburger at McDonalds your whole life. The men you’ve slept with however, have been sampling the burgers at numerous establishments since they were sexually active.
Burger tastes like boring burger to you because you don’t have anything else to compare it to.
The men have developed an advanced palate throughout their travels and can compare and contrast the finer points of each burger.