For many of us, our thoughts are used to create meaning. For whatever happens in our day, we have preconceived notions based on how we would like them to be. For example, if we see a friend with a new girlfriend that you're attracted to, immediately the seeds of jealousy are sown as you attach meaning to it. Why does he get a hot girl like that and I don't? Such thought, the attachment of meaning to it, and trying to fight the thoughts and make them go away, is the root cause of suffering, depression, clouding one's thinking, and destroying happiness.
What if we simply stopped thinking, or analyzing. The great psychiatrist Alan Watts once said that "he who thinks all the time has nothing to think about but thoughts, and lives in a world of illusion." When we stop thinking, and attaching meaning to things and just let things be, without judging, without attaching meaning, and just think that something just is amazing clears are mind and we are able to see reality in its purest form.
If we were to allow are thoughts to be, and realize that they are not reality, and they are not something that we can wish away, or touch and control, and allow them to be and flow like a river, all suffering and anxiety would end. We would still think, but instinctively, as nature intended. Our mental processes would see our friend with the hot girl and just process it as our friend with a hot girl. The driver who cuts us off while we're on the highway is, what it is, not what we expect it to be. Our minds and instincts are still there to cause us to react appropriately to steer to avoid the accident, or deal with any situation that comes are way, so the rest is chatter, or artificially created meaning.
If you can ever remember being in a situation when you felt overjoyed, try and relive it. You were probably not thinking at all, nothing in the world mattered but the moment. Or perhaps if you were an athlete, and you were on fire and everything you did was down flawlessly and you could do no wrong - it's known as "the zone" by some people. You may have remembered that as soon as you thought about it, the zone went away