A time where the chance for action (usually, but not always, sexual in nature) arises. When one sees such a chance, one must grab it (or, if you will, jump through the window of opportunity).
1. The Sexual Window of Opportunity. . .
Where one comes across a girl drinking a pint, and casually slips her a tab of rohypnol, thus creating a window of opportunity for easy sex later.
2. The non-Sexual Window of Opportunity. . .
Where one sees and old lady struggling with heavy shopping, the window of opportunity arises to help her. Remove a baguette, whack her over the head, and take her purse and sausages.
When used to describe oneself, it is a comic expression used to indicate a unique and eccentric nature, i.e. one who does not follow the norm of life.
Certain people use this expression to be hurtful and condescending, while others enjoy being recognized as extraordinary.
That painfully awkward moment when you are checking your reflection out on a car window, spending ideally over a minute grooming your hair or pouting YET there is someone inside the car directly looking at you confused and worried...you dont realise he or she is in the car so you carrying on checking yourself out.
then you notice them looking at you and you quickly have to run away forgetting everything which happened.
Shiv was totally guilty of window cringe the other day, thats why we didnt invite him for drinks tonight...the vain bastard.