Jack Palance played grizzled cowboy Curly Washburn in the 1991 comedy City Slickers. Curly's Law is defined in this bit of dialog from the movie:
Jack Palance in City Slickers Curly: Do you know what the secret of life is?
Curly: This. [holds up one finger]
Mitch: Your finger?
Curly: One thing. Just one thing. You stick to that and the rest don't mean shit.
Mitch: But what is the "one thing?"
Curly: [smiles] That's what you have to find out.
Curly's Law: Do One Thing
The same goes for Web 2.0- you don't have to know it all, or l"keep up" -- just find one thing that is meaningful to what you teach, and stick to that,