Why do tea leaves stick to the pot?

There is a pesky little irritation that applies to brewing tea, and to a lesser extent to coffee. And here on New Year’s eve, having a nasty cold and nothing better to do, I would like to ask about it.

Whenever you brew some tea, the leaves always cling to the insides of the pot, when you want to wash it. This is especially true for those pots, which figure a plastic strainer that you take out of the pot to clean – supposedly dropping the old leaves in garbage bin, instead of washing them out.

I was wondering why is that so, and is there some easily available solution to make leaves unstick from the strainer when you need to clean them out?

P.S. Happy New Year everybody!

Dispersive adhesion?