So very difficult a matter is it to trace and find out the truth of anything by history.

Working out what really happened is much harder than it looks, even with witnesses and records. Accounts are written by people with interests, memory reshapes itself to suit the teller, and what survives is not a fair sample of what there was. Confidence about the past should usually be lower than it is.

When you are reconstructing something contested, at work or in a family, gather more than one account before settling on a version. Hold your conclusion as the best current reading rather than the fact. And be especially careful with the story in which you come out well.