I recently set a writing exercise for a group of people, 90% of whom were over 50. They had to answer the question: "Are there any advantages to getting older?" I was amazed at how many of them came out with abundant and optimistic lists of reasons to say "Yes!"
I was surprised, because I could think of only six, and four of those are my grandchildren. My other two were seeing my children grow into adults I admired (as well as loved); and having the mental space to really appreciate tiny, everyday pleasures, such as my pillow, or a summer evening bike ride on the empty Monsal Trail. I could go on forever with this list.
I'm still thinking about the question.
Assuming we have enough money not to worry, and we are healthy, being old successfully - i.e. staying happy - is still a tricky thing to master. Death is all around us, and we're aware of how tenuous is our grasp on life, so we want to use our days in ways we won't regret. How we spend our days is how we spend our lives. And in order to retain our health we have to pay daily attention to keeping fit, eating well, not drinking too much. We need to keep cheerful and not complain about your aches and pains - or in my case, my tiredness and lack of energy. And we need to stay involved in the world and it's concerns, up to date with latest trends and developments so as not to become an old fogey, always doing new things and going new places so as not to be boring and bored. (Mixing with young people helps with all of this.)
It's hard work and it's a skill to practice - being old successfully. Weirdly, it reminds me of that poem that Larkin wrote for Kingsley Amis' daughter when she was born, Born Yesterday. He was wishing her well for her future, and being old successfully is a different venture, but it takes many of the same skills -
In fact, may you be dull -
If that is what a skilled,
Catching of happiness is called.