For most of human history, what was true when you were a child was still true when you became old. But our modern world is changing ever faster. We should hold our knowledge, assumptions, beliefs and expectations lightly, because quite a few of them are likely to be superseded. The social changes that have taken hundreds of years to happen in the West are happening within a generation in some countries. What seemed to be true about a country ten years ago is already out of date. So, be alert to change and live in the present.