This morning I tried a simple mental stillness meditation. I began with counted breaths -- 4 beats in, 4 beats hold, 4 beats out, 4 beats hold, repeat -- and focused my attention on relaxation, from feet to head. Then I tried to simply count and exclude all other thoughts.
I was struck by how noisy my brain is. The thoughts fought back hard, and for every one I managed to quell by forcing my mind to attend to counting, two more it seemed would well up to take its place.
Finally, after what seemed like a long time, I managed a few breath cycles with no other thoughts intruding. Immediately upon noticing that, of course, I started thinking about how I had briefly managed to stop the thoughts.
Eventually I ended the practice. The total time was about 10 minutes.