Name five things you can hear right now. You just came back to the room you were already sitting in.

Attention drifts out of the room without announcing that it has gone. You can spend an entire hour physically somewhere while your mind is in a conversation from yesterday or a worry about next month. Naming what you can hear works because hearing happens right now and cannot be done retroactively. It puts you back into the only place where anything is actually occurring.

Try it when you notice you have been elsewhere. Five sounds, named silently, however boring they are. It takes fifteen seconds and you can repeat it as often as you need.