Why Do You Wear That Scarf Around Your Neck?

So this one time (read: last week),

I went through this really obnoxious phase,

in which every time I wore a scarf around my neck, I'd insist upon asking each individual within a 10 foot radius... 

"why I do I tie this scarf around my neck?!?"

Inevitably, they'd shrug -

a gesture which I'd enthusiastically interpret as a passionate "I don't know, why!?"

and to which I'd thus respond by dramatically removing the scarf and cleverly pretending that

my head fell off.

Moral of that story:

I'm like, really clever.

The fact that the original tale involved a yellow ribbon and not an idiotically-tied scarf really didn't matter when there was such noteworthy acting taking place.

Anyhow,

to this day, that story has stuck with me every time I've gone to tie any sort of accoutrement around my neck.

Back then, tying a scarf around my neck seemed so retro - something someone from The Notebook would do (I obviously have a very deep wealth of historical knowledge). 

Today, however, it feels a little bit fresh - like it's been gone long enough now to be cool again. 

scarf: vintage paris, shirt: zara, shorts: nicole miller, shoes: 3.1 phillip lim

Like the bell bottom.

But how do you know? 

How long do you have to wait for an out-of-style trend to become an in-style throwback? When does it officially cross over from passé to vintage? 

How long before really bad highlights and Britney Spears-esque pigtails are intentional historical references rather than "fashion faux pas"?

And are there ever trends that are doomed to no revival?

hmm

Cheers.