You could call them "arrogant" or "overbearing."
Someone who constantly thinks and reflects on various topics can be described as contemplative or introspective.
A person who thinks nasty things could be described as pessimistic, cynical, or having a negative mindset.
If someone is from Beirut you call him or her Lebanese, since Beirut is the capital of Lebanon.Actually the proper response to his query would be this:You call someone from Beirut a 'Beiruti', the same way you may call someone from New York a New Yorker etc......
You could call them a trigger or a source of envy.
numerologist
Paranoid
Someone who thinks that being a hipster is to mainstream can be referred to as a jazz-maniac.
paranoid
that's a hypochondriac.
A self-centered person or egocentric individual is someone who thinks the world revolves around them.
You could call them "arrogant" or "overbearing."
God
A know-it-all!
That was a terrible question, because you call someone who thinks they are ill all the time a hypercondriac. So as in Jeopardy, "What do you call someone who is constantly under the impression that they are ill?" Answer: "What is an a hypercondriac?" That is correct!
they are usually called hypochondriac or suffering from Munchhausen syndrome
thoughtfulintellectualpensivesmart or shrewdcurious or inquisitive.I think first three are best thou