We were a little fearful of retirement. We discussed it and we paid a visit to a counselor to see if she noticed anything we might want to work on before finding ourselves more or less full time in each other's company. We have been at it for five years now and doing ok.
It was pretty clear to me that it would be different to not have a job to think about regularly. Retirement can take a rather well-functioning person and drop him in what seems emptiness. So, organizations and individuals are tempted to try enrolling the retiree in their activities. The recent retiree can be tempted to take up their activities and can certainly be enriched by doing so. For me, however, it was clear that I had never been free to spend time, money and energy at what I wanted when I wanted. I did not want to sacrifice the opportunity lightly.
Depending on one's health and other circumstances, retiring can seem a lot like winning the lottery: one is suddenly independently wealthy, a rich opportunity and a danger. The lottery is famous for cramming too many dollars into a life not prepared for it and thereby seriously damaging or totally wrecking a person. Retirement could cram too many dollars or hours and be a burden and a danger.
Most people retire after living a full life and that life, with its habits, interests, frustrated desires for travel or language or arts or crafts or skills serves as a surprisingly rich guide to spending the gifts retirement brings. The fear of being lost in an empty land with 'nothing to do' now seems baseless. There are tons of opportunities all the time. It still seems the main problem is a balancing act between commitments/plans and open freedom.