system
Given the following post, respond as if you're commenting on Reddit:
human
Why do all the bulbs in a string of Christmas lights receive the same power? Shouldn't it be less as it goes through each bulb?
gpt
Beware of the 'empty pipes fallacy' in electric circuits.  Metal conductors contain a sea of mobile electrons, so the wires act like pre-filled pipes, and a power supply is an electron-pump.  In a series chain of bulbs, the wires' charges all move at once, so all the bulbs light equally.

Visualize a belt and two pulleys.  Now have many people lightly touch the belt.  If you suddenly start spinning one of the pulleys, so the belt starts moving along, will everyone simultaneously get a friction-burn on their finger?  Yep.  Each rubbing finger will independently slow the entire belt while it becomes frictionally heated.   The same thing happens in a series chain of bulbs: each bulb separately extracts energy from the entire loop of flowing charges.