Slight of hand, card mechanics (basic card tricks, forcing, double lifts, dealing under, etc), memorization games (rubiks, deck order, X random numbers from Y crowd members), mental math (give me any two two/three/four digit numbers to add/subtract/multiply/divide I'll beat your calculator), day of the week calculation (give me your birthday/anniversary I'll tell you the day of the week)
edit: instruments, double jointedness
The primary key to any such interesting display is discretion. If everyone knows you play the piano, no one cares. If no one knows, and you hit Tchaikovsky's 1812 in the mall, everyone's shocked.
And once you can reliably flip any object a half rotation, one/two/etc rotations, it transfers fairly easily to similar objects, and to the juggling pattern.
Going from not juggling to juggling knives can be done in perhaps weekends.
Then, of course, you can do all the fancy multi-object patterns, but I've yet to see a reaction to three spinning knives surpased by five+ tennis balls. The five+ tennis balls are neat while the three (even just two) spinning knives is always a visceral holy shit please stop you're going to hurt someone.
edit: instruments, double jointedness
The primary key to any such interesting display is discretion. If everyone knows you play the piano, no one cares. If no one knows, and you hit Tchaikovsky's 1812 in the mall, everyone's shocked.
Going from not juggling to juggling knives can be done in perhaps weekends.
Then, of course, you can do all the fancy multi-object patterns, but I've yet to see a reaction to three spinning knives surpased by five+ tennis balls. The five+ tennis balls are neat while the three (even just two) spinning knives is always a visceral holy shit please stop you're going to hurt someone.
https://www.youtube.com/watch?v=gaDdrDdczO4
looks like he has some new ones