It's not about understanding, it's about preparedness. Operation Odessa (and later Stalingrad) became a disaster for Nazi Germany in the winter because it was supposed to be over in the summer. The troops were then prepared for winter in the Battle of the Bulge. There was much snow during the mountainside battles between Austria-Hungary and Italy during WWI, too. And Napoleon's greatest victory, Austerlitz, was in December. Winter was also the season for counter-attacking the Ottoman Empire, with major actions in 1443 or 1664.

_{*Lunatic*, n.
One whose delusions are out of fashion.}