Strange electric phenomenon? I don't understand this

We always connect one end of the circuit to a positive pole and the other end to the negative pole of the battery.

But... When I connect 2 negatives poles or 2 positives poles using the next configuration... The motor works and the light bulb shines.

ONE END OF THE LIGHT BULB -(battery1)+-(battery2)++(battery3)- SECOND END OF THE LIGHT BULB

As you can see, the light bulb is connected to 2 NEGATIVE poles...
Why can I light a light bulb using 2 (negative or positive) poles?

You've got three batteries, two cancel each other out, so you're running off just ONE battery.

As Nigel stated if you measure the voltage you'll see the voltage of one battery.