Since I finished the 16 puzzles, my scientists have become a lazy lot. Do I need them any longer or should I retrain them?

There are no more tech points needed, so your villagers (being a smart lot), don't do needless work..lol. So yes, retrain them

I let the old ones retire. Just keep them as scientists and they mostly relax, exercise, chat, tell jokes, etc. They deserve it.

Thanks. I tried to let my favorite farmer retire, Pawin. He died during the night, but he was 80 and happy. Most of what he did was "wait for someone." Chatting, telling jokes, even kissing the ladies.