One indication you've been single long enough is...

after seeing two people you know changed their relationship status to 'In a relationship' with each other, even liking it,

but one comments with the time-tested line between lovers and ending it with their term of endearment

then you...

you hear yourself making gagging sounds.

Post shout-out (a.k.a. senseless rate reaction): What happened to you? You've adopted one once, for the person you were with then. Remember?