Nobody is an extra. The quiet kid in the back row has a whole plot you know nothing about.

Quiet reads as empty and it is usually the opposite. Somebody who says little in a classroom has the same volume of thoughts, history, and things going on at home as the loudest person there, just without the broadcast. Treating them as scenery is a failure of imagination rather than an accurate read. Everyone is running a full story whether or not you get chapters from it.

Talk to one person this week you have never really talked to. Ask something real instead of making conversation. You will find out how much you had been assuming.