Maybe one has never had children, or else the children are mature adults no longer living at home. This would be a good time to review existing wills and other estate planning documents. Are the documents up to date? Is it time to make a child the executor of the will?
One may be a business owner and starting to think about what the future will bring to the business. Will it continue to be successful? It is not too early to start thinking about an exit strategy.
And if circumstances have been favorable, wealth may have grown. It might be time to rethink the estate plan, perhaps including gifts to grandchildren or charities.
For some, this might be a time of a second marriage. There might be very good reasons to get married, but there may also be very good reasons to not get married. If a marriage is going to happen, a prenuptial agreement should be considered, especially if there are children from a prior marriage.
For people who want to plan for well into the future, this is also the time to plan for retirement, and perhaps the less happy effects of old age.