Truck won't turn over, good battery, tried to jump?

[Z10]

Ok, here's the scenario: Took the child bride in the 72 GMC to see Lincoln tonight ( great movie, long almost 2.5 hours), walked out to the back row, (don't need any door dings from those super duties) all is good, it's where I left it. Stick the key in the ignition, nothing other than my park brake light is glowing? Dome light works, radio turns on, horn honks?

So, I call the baby girl to bring the jumper cables, she show's up in a flash,(just like baby girls are suppose to). Hook up the cables (yes, I've done this untold times over the course of the last 58 years).

Nothing! Absolutely nothing! No clicks, nothing??? So, I leave my perfectly good 72 sitting in the parking lot at 11:00pm and come home, to ponder my predicament. So, assuming that the truck is still in the movie parking lot in the morning, with my brand new wheels and tires still on it, what do you guys think is the problem?

Big Texas thanks in advance. Oh, and here's a pic just so you know that you'll be helping a good cause.