My feeling is that the witnessing state happens every day to everyone.
Let us ask: does that witnessing state happen when consciousness is fully engaged in something? No. At that moment you will not be able to taste the beauty and peace of that state, because that state of witnessing is then filled with perception and activity. Only when not too many things are happening in perception, will you feel the intensity of that witnessing state. Consciousness then becomes aware of its natural state.
So, this is possible when a certain calmness prevails, and not too many sensations occur. Peace of mind could happen when you go for a walk in nature, or at sunset, or on waking up in the morning. It doesn't necessarily have to come about through meditation or detachment.---Marc Beuret