The Concept of Time.

It was Jenga first, at which, due to her dexterity, vast intellect and some dodgy house rules, Kate beat me with ease.
Next it was 'Fishing for Frogs' in which I became entangled in a miasma of surreal concepts resulting in a 6-0 drubbing. I found this hard to fathom with there only being 4 frogs in the first place.
Finally, there was 'Puzzle Time' in which we had to complete 5 jigsaws before I had to leave to go home.

"I really have to go soon, Kate."
"It won't take long, Wull" (I am known as 'Wull')
"How long do you think?"
"Between 2 minutes and a hundred years."

Now, that's a 'window'.