If You Scream When Fire Touches You, That Means You Exist Day!
After going a few weeks of being ignored by bartenders, you start to wonder if you're really there. Every minute of your excruciatingly dull consiousness could just be the passage of a final dream right before your brain dies but right after the doctors have told your remaining family members (distant cousin who sort of remembers seeing you at a wedding 30 years ago), "I'm sorry, he/she is gone. Please collect his Dean Koontz novels from the bedside table as we have to turn over the room." Or you could be the dream in the head of a sleeping evil giant in a far off universe BLAH BLAH BLAH. Either way, you couldn't get a cab to slow down for you if you were in the middle of the intersection sitting on a wheelchair.

If you're certain the possibility of the words "I will always love you" being spoken in your frame of existence is so apocraphyl that you wouldn't even be able to hear them whilst eavesdropping on a conversation at a romantic restaurant (table for one, and yes, you've tried), perhaps you should see if fire still hurts. Go to the stove and hold your forearm over the flame. If you scream, you probably still exist. Either that or the little retarded gnome in whose head you exist as an amusing daydream has a great attention to detail. By the way, if you do exist, you're still the only one who knows it.