Disclaimer: I do not own Wizards of Waverly Place. I used TV Tropes for reference to research some facts.
Warning: since this is purely based on facts, this contains spoilers.
The first time he gets a girlfriend- Miranda- it's just too blatant. She's rebellious, gothic, feminist, not too girly. But mostly, when you look at her, the familiarity strikes you instantly. The same long black hair, styled similarly and almost of the same length, dyed with streaks in a similar way, similar structure of the face. You don't have to look too far to see that she looks almost like a twin of Alex.
So he swore that next time, he would be more careful and less obvious. That's how he ended up baby-sitting for a girl he had a crush on. That's how the Centaur-mess came up.
Enter Isabella. Cute, friendly, polite. Werewolf he found on Wizface. Where's the similarity? When he opened the door, there she was, wearing a cute top, a T-shirt, with a cute headband. The same way Alex dressed up minutes later. So all he had to do was close his eyes and pretend it was her. (But this time, he was confused. Was he trying to find her in Isabella, or was she trying to turn into Isabella?)
Exit Isabella and enter Daphne. He never even wanted to date her in the first place! She was clingy, melodramatic, living in the world of stupid teen magazines and surveys. Nothing like Alex at all? Wrong. Because when the rest of the group did not show up and he and Daphne were alone at the Art Museum, he was constantly reminded of the night he and Alex had at the Art Museum, fixing the mess she had made. Maybe that was why he couldn't bug out and run away?
Juliet. Blonde, vampire, sweet and uptight. What could she possibly have in common with Alex? Her name. Because when he heard that the name of Alex's character was Julia in Harper's "Charmed and Dangerous" books, he knew who the other half of his Surge would be. When he called Juliet by her name, he could pretend he was trapped in the books with Julia.
And now if you look at it from the reverse, when she wanted to make a fake ID to sneak into an R-rated movie, she stole the picture of his favorite weather girl, the one whom he found hot. When they pretended to be Max's parents, the name she chose was Diane Sawyer, famous TV newscaster and former weather girl.
So if you look closer, it is not too hard to understand. Now we only need to see what his angel will be like….
A/N: I had planned on writing this forever. I was stuck on Juliet forever, but finally I nailed it! XD see, this is why you should watch an episode again and again. :P hope you liked how my shipper mind works. Reviews would be awesome :D