Until the present pandemic, WW2 was possibly the last time the whole country had its backs to the wall. You never knew who'd survive and who wouldn't. Young fit men (and to a lesser extent women) were called away to serve overseas, with a real possibility that they might never come back, or might return physically or mentally damaged, or return to find their home and/or their loved ones gone. Against such a background, optimistic songs such Miss Lynn's were understandably popular.

Perhaps it's time for a revival.