What exactly is premature ejaculation?

Now I’m not going to spend too long on this because I’m sure most of you guys have a pretty good answer for this one already. There are a lot of formal definitions such as: Premature ejaculation is a "persistent or recurrent ejaculation with minimal sexual stimulation before, during, or shortly after penetration and before the person wishes it."

Or this one: “Premature ejaculation is an “inability to delay ejaculation to a point when it is mutually desirable for both partners”. I think this is a pretty good definition, but if you want to use another one, that’s fine. After all you should be using all your energy beating premature ejaculation, not defining it.