“Britain has a long tradition of taking young soldiers overseas; what was different in the First World War was their sheer number. Among all those serving in France by the end of 1915 were more under-age soldiers than the entire force that Wellington took to Waterloo exactly one hundred years earlier.
The connection to that event is stronger than one might imagine. A veteran who died at the end of 2002 remembered that in 1905 he had met a former boy solider who had served at Waterloo. His mother had impressed on him how remarkable the meeting was, and the memory had stayed with him all his life – a twenty-first-century link to the great battle of 1815. – Boy Soldiers of the Great War by Richard van Emden
(This kind of blew my mind.)