Emotional Shadow

Guess there are some emotions that one can never shake off, for they cling onto you like a shadow. It's not within total control of when they appear and disappear, though you know the conditions that will cause the appearance and disappearance. But as life goes on and situations present themselves such that it's almost impossible to control the appearance or disapperance of it. So then, how nice if the shadowy emotions can lie dormant until they're being triggered by only 1 or 2 varibles.