Children make believe, they do it readily every day, and without any formal training.
They will begin to play out whoever they are told to be with little doubt and usually with great concentration and individual belief. Secondly, being brilliant and great at any one thing is hard to achieve even for those of us who are brilliant. Acting itself, the basic premise, making believe you are someone else is actually easy to do. Like we said, it is a child's game. It is when adult rules are applied to the creating of this child's play that the work of acting begins to get difficult.