Put 95% or so in passive, then use the rest for a few gambles. If you lose it all, no big deal, make sure you're comfortable writing it off. This way you can get the entertainment value, playing extremely risky with this money but without taking on much large scale risk. You can use leverage or options trading to maximize the risk/return for this if it doesn't feel like it's enough to be fun.

Some people say lottery tickets are the highest risk portion of the portfolio, but for people who like looking at numbers as you're describing, I think this is a better option.