Birthdays, and other occasional reminders of one's mortality.
Discovering a new interest or activity that doesn't fit who you think you are, like sailing or golf.
A breakfast joint with real maple syrup on all the tables.
The salesman who leans in and whispers, "You can get this stuff much cheaper elsewhere."
The film breaks in the middle of the movie, and the theater is dark and silent.
The lightning sounds like it is much, much closer than it is.