We do not always have to connect bulbs and motors in a line (series wiring). We can also connect them side by side (parallel wiring).
This is actually far more useful and is the way that most circuits work, including home wiring, computers and televisions.
In parallel wiring some of the wiring is shared, but in reality each bulb is connected directly to the battery, not to the other bulbs, so if one goes out the others stay on.
