They know you too well when:

The bartender recognizes the sound of your Jeep coming down the hill and pulling into the parking lot, cracks a Molson Golden and leaves it on the corner of the bar by the door, which you grab on your way through the main bar to the back room to play darts. No words exchanged, not even a glance from either you or the barkeep. 30 minutes later he sends the waitress into the back room with a fresh Molson for you without you having even to ask. You and the barkeep finally say hello and goodbye at the same time when you go to pay your tab as you leave for the night several hours (and several Molsons) later. That was me for about 5 years when I played competitive darts out of an irish pub 2 nights a week year round, about 20 odd years ago. Barkeeps nickname was Gumby.