Why don't I gamble?

Even though I live in the gambling capital of the US, the answer is simple, really. I'm too good at math. On the radio I heard a commercial for a parlay in town. Basically bet $5 and possibly win $1,000,000. The catch: you have to win all 20 games (NFL, no less). I did a quick calculation. The odds are roughly 1 in 1,000,000 that someone will win 20 out of 20 games. In other words, that $5 bet should win $5,000,000 back to come close to breaking even. That's a 20% payback rate, and I didn't even count the fact that ties lose. Geez, what a ripoff!