Mazda5 Stalled

After driving for about 10 minutes (and before that had the car warming up for 10 minutes) the car stalled when I tried to start off at a set of lights on the top of a hill. The light turned green, I pressed on the gas pedal, and the car just died. I went into park, re-started the car, and like a typical male, sped off the line by spinning my tires in embarassment, getting a smack from my wife.

If this was a standard, I would assume I did something, but I have an automatic. It is a little scarey when a month old vehicle does it. The temperature was around -4 degrees celcius (~25 degrees Fahrenheit) this morning, but it has been as cold or colder most mornings since I got the car.

Has this happened to anyone else?

Cold and on an incline? I wouldn't worry about it unless it happens again.