That's the thing. It rarely leaves my desk. If ever it does, It will be on my dining table where I usually work. Unless, my cat, who is always sleeping, chewed it, then I would understand why this is breaking . . . hahaha
No scratches on any part of the unit. No damage on the Retina display. This is why I asked the service centre if it is the temperature since I live in a tropical country. They said, no. This damage is still a mystery .
Conclusion : Sensitive screen.
Solution : I guess I'll just get it checked at an Apple Store when I go to HK or China this year. Before then, I will try not to look at the edge of the screen. hahaha