You have yours correctly wired. I can only assume, if those that you've seen had a red wire on one side, and a black wire on the other, and the circuit was working, then whoever wired it used incorrect insulation colors.
If you wired a circuit breaker with a positive on one side, and negative on the other, then as soon as the circuit was energized, the breaker would pop, as it would be a dead short.
In general, a (very simplified) circuit, will "loop" from the positive power source, through an overload protector, (fuse or breaker), through a control device, (switch), through a load, (pump, light, start motor, etc.), then back to power negative. There are a number of different control means, but the generalities are still the same.
Roger