Does a standard lightbulb in a three way socket do anything unusual; what do the three way sockets really do anyway?

A three way socket is set up for a special bulb with three elements each is turned on as you rotate the switch. If you put a standard bulb in the socket it will light up on one of the setting as you turn the switch. If you continue to turn the switch at some point the bulb will go off.

A standard light bulb will only go on or off. So the 3 way socket has to be twisted extra to turn it off, because it has 3 ON positions.

The special bulbs for these old lamps have 2 separate light emitting filaments inside and have 3 electrical contacts on the base of the bulb. Normal light bulbs have but 2 connections on the base and one filament inside.

Three-way sockets are intended for multiple filament bulbs. A regular bulb will just be lit in two of the three switch positions.