Life is full of uncertainty, isn't it?
Sometimes when you thought you know someone inside-out, but the fact is, you're still miles away from within. By using your OWN thinking to explain a person's behaviour can sometimes, well, misinterpret the person's intention because at the end of the day, it's only clear that each and every human is different, with thinking, and up-bringing which eventually lead to who she/he is today.
Recently, someone commented that I'm a person that is hard to understand. Yes, I don't deny that. If my Mother who lives with me for 20-years can't totally understand me, who else dared to say that he/she knows me well enough? Perhaps, those who're really close to me will know what's my next line, what am I laughing at without having to say it out, what I wanna tell with just eye contact and not verbally, but do these people know what's my solution at the end of the day? Absolutely NOT!
Well, nothing is a certain, including you, yourself.