The best way I've found to remember how electronics works (in terms of resistance and voltage) is the water
through a straw method. The resistance is basically how hard it is to suck the water
through the straw. The narrower the straw (narrower the wire) the harder it is to pull the water up the straw (the more resistance). The harder it is to pull the water up (higher the resistance) the more pressure (voltage) is going to be needed to get that water up with the same volume per second of flow.