Retirement is mandatory at a certain age for those who are in employment and voluntary for the self-employed. Overnight, they find themselves without work, without contact with their co-workers and without any goal to look forward to.
Life ahead begins to look bleak.
Sometimes depression sets in. That way, your finacial resources, investments and outcome can be planned. You should start avoiding stress and keep yourself physically and mentally active. Pensions, savings, income from property and investments should be properly planned by taking the advice of reliable consultants. If you are planning on a second career after you retirement, it would be worth your while to set aside a few hours a week from an earlier age, to work towards that career.