Please get these two words very clear: reacting and responding. If we are reacting emotionally we can learn from that. What made me become so sad? What made me become so depressed? What made me so insecure? Because you might have had the thought: maybe my own child could be like this sometime. So we can create a huge story from a simple incident that you have seen on the road. If that happens, you can reflect on it: Why am I reacting? So that becomes an object of meditation.
And maybe in another situation you might be able to respond. Respond very clearly, very calmly, with a still mind, doing what has to be done. So you see the difference very clearly: Ah, see what happens when I react and see what happens when I respond. Just see the difference.
And the same principle applies to what is happening internally. When we are meditating, someone who is habitually reactive can be reactive to what is happening in meditation also. To take an example, supposing your knees are in pain. You can say my knees are in pain, who knows, my knees might break, I know some meditators who have broken their knees – and you can create a huge story from the pain in the knees. And from the pain in the knees you can have anxiety, you can have fear, you can have insecurity, you can have all these unpleasant emotions. So responding would be just observing the pain and learning to make friends with it, and if it becomes unbearable you change the posture.