Gonna throw in my vote for the tail-end of fall. When it's almost-but-not-quite winter, and every morning is chilly and frosty. There's something really peaceful about the quietness of it. And it tends to be right in-between major holidays, so the break from "being present" is kinda nice, too.
Also tends to coincide with pumpkin spice season. Despite all the recent negativity about it in recent years pumpkin spiced everything is an absolute favorite of mine.
Fellow introvert. Don't really know what to say other than this post tracks. The value of just "being" is really important.
Hope your week is well. And everyone who reads this, too.