You could be sitting for several minutes or even hours but never get into a meditative state even though you have managed to force your mind to have no thoughts by concentrating or focusing all your attention on something. Meditation is the cessation of mental activity and this means the mental doing that we do in our mind stops and our mind rests quietly. If we wilfully force our mind to stay quiet, it is a doing. If we strongly concentrate or focus on one specific thing, then it is a doing. Meditation is a state of non-doing being.
Thoughts arising in the mind due to whatever happens in the body or in the surrounding is not mental doing, it is just an arising phenomena. To compare, breathing happening in our body is not physical doing, it is an arising phenomena and it continues to keep happening even during deep sleep when our body is at complete rest. Meditation is complete rest to the thinking-mind. Only the aware mind is awake and alert and it simply sits as a witness to all that arises in the present moment.
Getting back to your question, it takes just a few seconds for me to go through a mental shift into a meditative state now. But in the beginning, 30 years ago when I started with the practice, if I am sitting along with my mentor or guru who initiated me into the practice it would happen within a few minutes and if I am sitting by myself it would probably happen after fifteen minutes sometimes or never happen most times. But if I practice some energy movements or gentle yoga stretches before sitting with an eyes open practice called FGCB, it would invariably happen within a few minutes. Please read the following article if you are interested in learning more about it.
Selvan Srinivasan · 1y
How can you maintain mental and spiritual balance in today’s world?
Note: above picture copied from a google search of “rope walking images” Your question is very apt because never before in human history has there been so much disturbances to our spiritual balance than in today’s w