The purpose of meditation is to pacify and calm the mind.
When our mind is calm, we stop having worries and afflictions, and therefore we enjoy true happiness; but if our mind is not calm, no matter how pleasant the external conditions around us, we cannot be happy.
Usually, we find it difficult to control our mind. It is unstable and vulnerable to external circumstances, when we don't get what we want or lose something we like, get discouraged or feel upset.
We suffer these changes in our mood because we get too involved in external situations. We are like children who are excited to build a sand castle on the beach, but begin to cry when the waves destroy it.
If we practice meditation regularly we will create an inner space and mental clarity that will allow us to control our mind whatever the external circumstances, so we will enjoy inner peace and serenity at all times. And from that mental space of clarity and serenity we will have the freedom to choose to react with a positive and constructive attitude to any situation that comes our way.