The pressure of getting a long-lasting erection or having a big enough penis can become such a focus to a man (and his partner) that it dominates his experience, not allowing him (or his lover) to be present, connected, and all of the other things necessary for an amazing sexual experience.
Silent devastation has befallen many a happy partnership due to erectile concerns. Both the man and the woman feel helpless in a situation that can have many concrete solutions. Being able to talk openly, honestly and with vulnerability about ED begins with seeing the other person's side.
We may be unable to share our most intimate sexual secrets with our partners, but we seem more than willing to expose ourselves publicly. Why the obsession with everybody else's sex lives? I suspect it's our way of seeing if we're keeping up with the Joneses.