What are the problems of having an elderly population?

The problems about having an elderly population is that in an elderly population, the older you are, the body can't function as well as it used to when it was younger. The brain can't calulate information as fast. Since the body is weaker, the old people can't escape situations as quickly. For example, if they trip on something, they will have trouble getting back up. Also, bones of the elderly can break more easily.

Nationwise, more money would have to go toward healthcare to make sure the elderly don't die.

Also, elderly people would be less interested in big changes (sometimes they like to keep things the old-fashioned way).

I think that in the future someday that the elderly bodies could be fixed and renewed to the same behaviors of younger bodies via... nanobots! So, in the future we could have an elderly population without the negative consequences.