Try this tonight. Turn off the lights, close the curtains, and wait until the room is as dark as it gets. Then keep your eyes open and look into the darkness. You might expect to see black — complete absence, the visual equivalent of silence. But that is not what happens.
»Dump the first espresso of the day.« That was the advice, I saw in a reel the other day. A guy standing in a spotless kitchen, speaking with quiet authority. No drama, no irony. Just a clean instruction. Even if you single dose. Even if you weigh your beans to the tenth of a gram. The coffee sitting in the dead space of the grinder overnight will have oxidized. It will dull the shot. It is not worth drinking.