My Analogy Attempt

  Imagine that you're sitting on your porch. You're enjoying the sweet, warm sunshine when this cat comes wandering into your yard. You just watch it, as it watches you. You think "that's kind of a cute cat, I wonder if it belongs to anyone." As you're thinking this, you notice the cat isn't wearing a collar or tags, so it must be a stray. 
  At one point, the cat comes towards you. But you're comfy in your chair! That cat has got to come to you if it wants petted. As it comes closer, you reach down just a bit, but that spooks it and the cat runs away. So you just sit back in your chair, go back to enjoying the weather, and wonder if you'll ever see the cat again.
  A few days later, you're sitting outside again. The cat comes around the corner. This time, it comes right to you. After spooking it last time, you just sit there and see whats it's going to do. It begins to weave between your legs and purr, rubbing it's face against your calf and being super friendly. So you think "it obviously wants my affection." You reach down to pet it. This time, it lets you stoke if a few times, from head to tail. This is the softest cat in the world! After a brief enjoyable petting session, the cat runs off again. What the fuck is up with this cat? Why does it keep running away from you? Now you're left on your porch again. Alone. You were alone before, but you didn't notice really until you felt some company. 
  This time, the cat stays away for a while. But you sit on your porch everyday, waiting to see if it wanders into your yard. When you see it, you just remember how soft it was and pray that it comes over to you again. But as it gets closer, you notice a bright-ass collar on it with a shiny tag. Someone has claimed the cat. In your mind, that cat was YOURS. You can't help but think someone got close enough to that cat, not just to pet it, but close enough to put a COLLAR on it. AND to get it tagged? What does that owner have that you didn't? 
  The cat, collar and all, comes to you anyway. It rubs against your legs and wraps its tail around your ankle. But you're pissed! "Go get your owner to pet you", you think. Stupid cat. If it really wanted to belong to you, it wouldn't run away all the time. The cat gets tired of your tantrum and trots back across the yard and disappears. Probably to go get its stupid tag shined up. Wonder if it's name is Stupid. 'Cause that's what it is. Stupid.
  For a while, you sit in your spot and other cats wander into your yard. Some are very pretty. Some are REALLY friendly. And when you pet them you think, "This could be my cat." But in the back of your mind, you remember how soft that first cat was. And how no other cat feels quite like that one. So you just stop paying attention to cats for a while. Focus on enjoying the sun and the quiet of your porch.
  Then one day, when you least expect it, that first cat shows up. You almost forgot about it. ALMOST. It makes it's way across your yard and keeps direct eye contact the whole time. You realize there's not a glare from it's tag and the collar is gone. In your bitter mind, you think "What happened to your fancy collar? Did your SUPER SPECIAL owner take it?" Before you can continue your internal rant, the cat leaps onto your lap. Holy shit! That was unexpected. As it curls into a ball and begins to fall asleep, you feel that anger fade. You don't know what this cat has been through, or why it's back, but it's here. It's on you and it's comfortable enough to sleep on you. 
  So now you're sitting here with this cat on you. It's not your cat, but it's not anyone else's either. But it's with you, so that's gotta mean something, right? You're careful when you pet it, for fear of spooking it. You have to pee, but you're not going to get up. You don't sneeze or cough or anything. The soft cat is back and you don't want to disturb it. So now you sit on your porch, enjoying the warmth of the sun, and the warmth of the cat on your lap. 

This is the EXACT situation I'm in with my ex-girlfriend. She is the cat. And I was the comfortable loner that forgot what it felt like to not be alone.