Mind is most capable of expressing itself in a fitting form. Very often man expresses his thought in any conversation that may be going on, which perhaps has nothing to do with his thought. And as his nature is, man looks for a scope for expression of his thought, and he easily gets it. In a serious conversation one can find scope for a joke. Even in tragedy one can find comedy, and in comedy one can find tragedy, if one's mind happens to dwell on sad thoughts. This shows that the mind always seeks for a scope for expression, and situations outside generously offer the scope.