When you start to feel a little sad, anxious, or irritable it’s not the mood that does the damage but how you react to it. The effort of trying to free yourself from a bad mood or bout of unhappiness – of working out why you’re unhappy and what you can do about it – often makes things worse. It’s like being trapped in quicksand – the more you struggle to be free, the deeper you sink. [..] We get drawn into this emotional quicksand because our state of mind is intimately connected with memory. The mind is constantly trawling through memories to find those that echo our current emotional state.
From Mindfulness: A practical guide to finding peace in a frantic world by Prof. Mark Williams