My Disappearing Act

When I use my bathroom I leave the door open because it's only me and because Alvin likes to follow me in there.  He always comes in, does a circle and goes back out.  I can count on him to come in again and do the same thing.  He then tends to wait out in the hallway.  What is interesting is that even after he has come in twice and clearly sees where I am, when he is out in the hallway and I call him, he isn't able to figure out where I am.  I am able to spy on his through the space between the door and the frame.  My bathroom is unusually small and when entering, you can either go straight for less than eight feet or you can make a very small turn to the left, which is where the toilet is.  There are no other options, and yet, when I call him, and on the times that he eventually walks into the bathroom, he will keep looking straight ahead or even look to the right, which is where the bathtub is.  It usually takes me waving my arms for him to look left and "find" me.  What is particularly interesting is that he always looks terribly surprised and relieved to find me there, even though he just saw me there less than one minute before.  All I can say is, thank goodness I live alone because I look like an idiot sitting on the toilet, calling a dog, and waving both hands wildly in front of me to get his attention.......how much you want to bet I continue living alone for all of eternity, because one night of our antics in this house would be sure to scare any roommate or suitor away.  I'm not sad about it because when I put Alvin in bed with me and he rests his little chin on me and I feel his hot breath getting slower and deeper as he falls fast to sleep, I am reassured that as long as we have each other, we'll be just fine.  And yes, I realize that I sound like the crazy dog lady.