Our mind is like the ocean.
At moments it looks calm, relaxed and inviting for us to jump in. Yet sometimes it's rough and dark and we want to run as far away from it as we can.
The interesting thing about the ocean, however, is that the surface can be misleading. If we were to put on some scuba diving gear, plug in the oxygen and dive beneath the surface, quickly we'd get far enough below the surface to discover there's a calm that is accessible to us, regardless of what's happening above us.
Meditation teaches us to dive beneath the surface and discover the calm that is ever-present.
Headspace have some great videos like this one to get you going.