A living a lifetime in a moment

I don’t know if anyone else has had this happen. You are out somewhere and you have to stand in line or something like that. But right beside you is someone. Not just any someone but someone who makes you go wow. Suddenly you start imagine meeting them and trying to figure out what they are like. Before you know it, you’ve invented an entire story around them and what things would be like if you knew them.
In fact you get so wrapped up in it all that you don’t even say anything to them and before you know it, they’re gone.