It is a very big decision because you are going against what your biological instincts and everything that you were brought up in (indoctrination by society, morals and values, ethics, etc.). As for the biological instinct alone, this self-preservation instinct (called the 'SI' - survival instinct) is such a powerful force to overcome such that most people who may want to CTB, may get hindered, if not outright stopped by that alone. Then of course, assuming one overcomes the SI, one has to ensure that his/her method will work (done the research, acquired the materials, practiced enough to ensure reliability and execution), and finally, hide it from everyone in the world that is looking to intervene. All of these factors make CTB'ing a big decision.