Yeah, I do that all the time - (in fact I used to do that with books too in Primary school, where I'd be so engrossed in the book somebody could shout my name, or people would leave the room, and I wouldn't hear them or notice). I also do it with a tile say, or a leaf, or a section of wall, or pretty much everything and anything at least a couple of times a day.
I wouldn't call it a meltdown, as a meltdown is tied to severe emotional and psychological distress. Basically when you're having a meltdown you feel like you're in so much intense unbearable mental pain that you can't take it anymore... and then you crack - rock, scream, cry, injure yourself. Sometimes when I reach that pressure point I lie down and I can't get up - I lose all ability to move my arms or legs, complete paralysis except I can sometimes turn my head, but my mind is still racing, and I can end up like that for over an hour.
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Into the dark...