You decide to bake some cookies, but discover you're out of vanilla. No problem. A quick trip to the grocery store and you'll be all set. You get to the store, run in, grab the vanilla, head for the check-out, scope out which one looks the least busy, get in that line and the next thing you know you're in slow-mo grocery store hell!

How do you always end up choosing the slowest line? The people at wired.com have distilled down what scientists call a "queueing" theory which explains it for you. It involves three factors:

1. Grocery stores open a specific number of lanes depending how many customers there are. But any minor delay (like a price check) can cause a major back-up.
2. The odds are always against you; if 3 lanes are open, two out of three times you'll choose a slower lane.
3. There is a better queueing philosophy, (like the one they use at Best Buy at Christmas or Barnes & Noble year-round) backed up by mathematical theorem, which is indeed faster. This is the system which uses one line and people are served by the clerk that is open first. However studies have shown that people don't like it and prefer to choose their own check-out line because it gives them a feeling of control.

Stupid us!