Why we do what we do?

Couple of days ago when i read through the status of some of my friends in Facebook, i came to know a fellow college mate had committed suicide. I was shocked and at the same time pondering what could have led him take such a decision. After all he was a young man with his whole life ahead. What makes people do things that aren't right. Or was it right for them? Were all their paths doomed and they were in a deadlock suffocating and deciding to end the pain. Do we have the right to end our lives? Are we winning over our problems by ending ourselves so that we have to suffer no more? I was thinking why do some people decide to take others life? Haven't we all read news of a people committing murder on their own loved ones. what happens to these people? They sure were normal individuals had normal lives. Then is it the hardships or some problems they encountered changed them and their response to it? Do all the people who commit suicide are in some form of depression? Why is it that some people inspite of worst sufferings in their life come out of it and make a way out and live life and even be successful. Are these people destined or do they make their destinies? What is the truth of this existence that we all have to come face to face and become victorious.
I have seen people (fighting cancer)  who will be having just few days left in their lives but still with all their pain and sedation with drugs still gleams hope that one day everything is going to be fine. Why didn't they decide to end it? There are people maimed after an accident, probably going to need support for the rest of their lives why didn't they decide to give up? why is it that some come out of bleak situations and turn their life around. Are they just lucky? Or do they have special blessings from god to change their life around. I feel myself as too insignificant to answer questions of this magnitude. These very questions that change meaning of life.
But i do believe "Mind" is the most powerful instrument in the hands of man. It neither is the brain nor is the heart. The soul, the conscious whatever term we give it. The Sanskrit verse goes"Ya dhrishti sa shrishti"  meaning what we visualize in our minds that is what we create. There cannot be anything more powerful in a human being than the power of minds. Bhagvad Gita states that controlling the free mind and bringing it to believe in God is the only way to free ourselves from this drudgery of never ending cycle of birth and death. That's the reason we often hear words and saying think positive. These aren't mere statements of motivation, subconsciously we do become what we think we are. Why is that some people respond to stress in a more positive manner where as some are just bogged down? It is the mind that changes the way we respond. Controlling the mind is the only way we control our lives. Which is easier said than done. But religion, philosophy and a good family support and friends makes most of us come out of the wretched time and live life in much more peaceful and positive manner. Hardwork, honesty helps us stay positive and in turn give positive vibes to our mind. As we are in a generation where Facebook friends outnumber the real friends. It is time we educate this generation the value of good relationships. Sometimes after a hard day all we need is a good hug or shoulder to cry on. When we let out pain we find purpose even in the bleakest moment of our lives. Confiding into someone whom we trust sure may not solve the problem but it can let go the burden of holding on to it and make us work towards a rational solution.
This life is a gift for us from god. We didn't ask for it and hence i do believe we never possess the right to end it. Getting impulsive and taking a wrong decision gives us no second chances.