What was the silliest mistake you made when playing VV2?

Mine was when I turned on a game after a couple of days away to find the 20-odd villagers all starving with over two hours to go before the next set of crops and still 30,000 tech points needed to get L3 Farming. I didn't feel like nursemaiding them through the problem so I clicked on Restart. As soon as I did that I realised I hadn't yet got L2 Farming, which would probably have saved them all!