Keep on learning

Research shows that challenging the brain in new ways can help to keep you mentally sharp. While you're working, that often comes with the territory: meeting new people, mastering new skills. But when you retire, you may have to be more proactive.

You can — and should — keep discovering new things in your retired life, too. But you may have to seek them out. There are plenty of ways to do it, and crossword puzzles and sudoku are only the beginning.

Travel, whether it's to a nearby city for a day or a far-flung destination for a month. Walk in nature. Take an adult education course at a community college. Whatever you choose, be sure to also get offline: More screen time has been linked with worse mental health in retirement, while more physical activity has the opposite effect.

So with some planning and challenging ourselves, retirement can be an enjoyable phase in our lives.