Meditation is prolonged concentration on something. Perhaps what you practiced was exactly "thinking about nothing and keeping your mind blank"? That would be the opposite of meditation and could be harmful, I guess. There are very subtle objects used in meditation, like light or space, but it's definitely not nothing.

> Perhaps what you practiced was exactly "thinking about nothing and keeping your mind blank"? That would be the opposite of meditation and could be harmful, I guess.

I mean, it requires prolonged concentration to clear one's head -- but I'll admit that I'm not a meditation expert. Perhaps I was taught incorrectly.

What thoughts should be running through your head while you meditate?

There should be no usual analytical activity in your mind during that time. Meditation is a lot like watching a still thought with your mind. Beginners pick simple objects like a black triangle on white background and try to keep their mind completely still, but with eyes open, with no other thoughts for 5 mins. People here that do software can easily achieve photographic quality meditation on simple shapes like that triangle. Then you increase complexity and start choosing proper objects like a little Buddha shape. The added complexity makes meditation difficult: the 3d image (which is a reflection of the object) gets blurry, dim or the attention is outright dragged away by other thoughts. It's like trying to balance on one leg with strong unpredictable winds. The goal is to develop strength to balance the mind and properly reflect complex static objects.

Then you switch from objects to ideas and that's a lot harder, but that's the actual goal. For example, you think a lot about the nature or idea of software. Once you think you've found this idea, you sit and spend 5 mins meditating on this idea. Ideas can't be drawn, they don't have shapes and our mind is not really suited for dealing with ideas.

Meditation is addictive. Even at the early stages you'll notice the flow of something thru your body during meditation and the weird, but pleasant feeling of physically stretching out your brains. This addiction is considered an obstacle, so the usual advise is to do a few short sessions that stop once you start noticing that feeling.

Your daily thinking will become sharper as you progress, and you'll get this feeling of physical balance. If it's not the case, you're doing something wrong and you'd have to seek an in person advice.

One particularly dangerous mistake is trying to clear mind of thoughts and make it blank. Tsong-kha-pa wrote a good deal about this mistake in his books to warn people.

Thanks for this reply! I never quite understood what people meant when they said they were going to meditate on a thing or an idea. This clears things up a lot.