Thinking happens automatically. Unless you're consciously directing it. Like breathing.
With practice, a person can learn to stop thinking altogether for short periods. That's called meditation.
When thinking stops, one realises that awareness doesn't. In effect, thought gets decoupled from awareness. The experience is generally very pleasant. Blissful, even. It's often described as transcendent.
When thinking stops, and awareness becomes a person's sole cognitive experience, a few things happen. Firstly, you get a break from the incessancy of your own thoughts. For many, this simple benefit more than justifies the practice. But for many more, they realise something much bigger has happened: they've woken up.
It's as though all the thinking was a dream, and now they're awake. This realisation is so profound that people often claim it's the most significant event of their life. A whole new dimension within consciousness opens up. And with it, a whole new trajectory.