Thinking about 'How I am able to think of myself'

         I always have these thoughts about concepts like 'self' or 'consciousness' etc. but I never had more chances to discuss  it with others. I guess at least by jotting down some of my ideas, I will be able to make the picture clearer for myself and I can start a discussion with you people as well.
         First of all, how do we define consciousness? Is it the thought process initiated when you try to question yourself? I mean like 'who am I?' or 'What am I?' etc. All the thought processes happen inside our brain only. So, when an entity which is 'intelligent' can question itself or let's say 'realize' its existence, is it what is called consciousness? To put it in a better way, is it possible to be 'intelligent' but not 'conscious'? i.e. how do we separate intelligence and consciousness?
           A small child say of age 2-3 years is intelligent in a normal human being sense of view. But is he conscious? Is he aware of his 'existence'? Does he 'feel' his existence? I some times think we unnecessarily glorify this term called 'consciousness'. What I mean to say is, maybe this realisation of 'self' is inevitable given the presence of 'intelligence'. Maybe this is what happens in case of the 3 year old child.
           Maybe when an intelligent being(say small child) learns to distinguish between things similar to itself, the natural next step is to distinguish 'itself' from others. For this to happen, the senses through which it perceives outside world plays an important role in my opinion. Some sort of self feed-back should happen to these senses which then results in recognition of self. Take the example of  Vision. Something like say mirror might play an important role here. When the child sees the outside world it questions it, remembers it, analyzes it and takes decisions based on it. If I put a mirror before it, it will try to question it like 'Did I see it earlier?', 'What is it?' etc. When it sees itself in the mirror only, it realizes that  it is seeing 'itself'. If this is correct what are the equivalents of mirror in other senses? But does this mean a thing which is intelligent but has no senses can't be 'aware of itself'? Of course, without senses/inputs there is no point in being intelligent.
          Another basic question is how do we even test whether an intelligent thing has 'consciousness'? Does all living things like ants, birds, insects have 'consciousness'? They definitely have brain and are intelligent, for one thing.
         Another interesting aspect is if we take 'consciousness' for granted like we took 'intelligence' for granted to look at 'consciousness', emotions and other 'thoughts' attached to 'self' might be the next logical step.(or is it not?)
          Let me stop here for now. I sometimes think the most challenging thing for our race is to figure out "How we are able to figure things out" or as I like saying "How are we able to think about brain using our brain".
         When one sees all this from a still broader view like life being a negligible part in such a huge universe which is in existence from billions of years, it feels kind of weird. Once we realize how trivial our existence in this vast universe is, our everyday  worries, goals etc look comical sometimes. We fret over things like bad food in mess, stupid weather etc. Even 'big' things like 'corruption', 'war' etc seem so silly from the point of view of the universe.....
         I only wish I get answers to at least some of these questions before I 'die'(what is death anyway?).