Hi vespertine
I started thinking about this when I started reading in the media a few years ago the first signs of worry that there will be fewer younger people than older people. I did the maths and thought that about that time I'll be hitting 60. And it occurred to me that this meant lots of opportunities to keep working, because they'll need us!
The thing about DH being a teacher came from an article in the weekend papers a couple of weeks ago. (We always end up having debates over things we read in the weekend papers.) They were talking about how they are really worried about certain professions in NZ, because of a worldwide shortage of skjills and other bigger countries will entice people away from here with higher salaries. They listed a whole heap of professions (everything from plumbers to university lecturers) and it included teachers. DH said "I wouldn't mind retraining as a teacher" and I thought that would be a fabulous idea. Because you could enjoy your new career at that age, knowing that you didn;t really HAVE to work. It got me thinking about what I might do in my 60s and 70s if there is a labour shortage.
On the subject of the fears of population decline because people keep having children - you know, personally I don't really care if the entire human population dies out in a few hundred years, and honestly I suspect that it might. It would give this planet and all the other species A BREAK. I just feel sorry for the last people left behind and what they might have to go through.