Having joined the Dutch army before the invasion of Holland by the Nazi forces, Sytse was captured and sent into Germany where he had to suffer years of forced labour in a POW camp. I know little of that period in his life, but it did take a severe toll on him. The only thing I heard him tell me about that experience was that he and his fellow prisoners had been used as guinea pigs for certain tests. One such test involved being fed soft plastic cubes which were imbued with nutrients and that they were told to chew. The Nazi’s thought the cubes might be a way of preserving food for soldiers far from Germany… sort of a ‘Ready-to-eat’ meal invented during the Second World War. This was to have a serious health effect later in his life.
After WWII ended, Sytse returned to Holland and, since he was still a soldier, had been given a period of time to recuperate his health before being returned to active service. What he chose to do was sell ice cream products by tricycle. As you can tell by his attitude, he enjoyed this period of peace in his life.