While it is normal to wonder how an ex is doing, the only socially appropriate way to speak to eachother (given your circumstance) is when you bump into him face to face and say hello out of respect for eachother.
No it isn't normal IMO to create Facebook accounts to try and check out how an ex is doing. Unrelated to your circumstance (but similar)- If one has blocked the other person from viewing their Facebook, the hint should be obvious to the person being blocked. I would have blocked the person's profile right away if I suspected that they were only trying to view my profile just to see what I am up to now.
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Your Aspie score: 130 of 200
Your neurotypical (non-autistic) score: 88 of 200
You are very likely an Aspie