There's a healthy balance. Don't constantly try to avoid bad feelings and run from them, but don't let yourself dwell on them and prolong them. Let them be. Let them come and let them go without resisting. Just observe. Thoughts and feelings are clouds on a clear, peaceful sky. The more you practice this, the more natural it becomes and your mind is more meditative throughout your day. It helps stresses to not build up in the mind and remain there after the actual stimulus is long gone, helps you remain more calm and centered more often.