Why y'all make such a big deal out of everything?

Ok, he didn't recognize her and she found it funny, what is the big deal about it? We don't even know how long ago it took place and even if that's recent that's not like Selena hangs out in the same circles than P. Diddy so even if he acknowledges her name he could still not recognize her in person, even because Selena is always in caps and loose clothing when in her off duty time