Vipassana

Some of my reading friends are shurly wondering about a couple o things i'm writing and may not know, what i am doing here.
We're doing vipassana meditation. The way mahasi sayadaw, a burmese teacher taught. This is the way to practice meditation the closest to as the buddha himself meditated.
Vipassana means: seeing clearly. We try to see clearly who we are, what we do, think, feel, say, ... Every detail, every moment. As the buddha said, when one is walking, one knows that one is walking ... We try to be mindful as long as we are awake. even when we are not meditating.
The meditation practice is split into 3 parts, mindful prostration, walking and sitting. As much as duties allow. If we have duties, they should be done mindful, as well.
During sitting meditation, for example, the mind is with the rising and the falling of the abdomen and always goes back there. If a thought arises, we not thinking, thinking ... Until the thought goes away if we hear something we not hearing, the same when we smell or feel or taste something or if pain arises. Every sensation that occurs is to be noted and than the mind goes back to the rising and falling of the abdomen.
Weard things do arise sometimes. But whatever comes up is just noted, while the body remains unmoved.
That's the beginning. There are further steps, but this is the base.
From doing zazen for very long time i was used to have a good concentration for a period of time. a strong concentration helps but is not necessary to have. we do not concentrate at "not to think" or on how many times we breath in and out. If there is thinking, thinking is just noted as what it is, usually by noting it it disappeares anyway. That's a concentration from moment to moment. Nothing spectacular.