Did it? Or did Reagan have clear memories of WWII - when he was 30-ish years old - and the horrific level of death and devastation which even conventional bombing had inflicted upon Europe and Japan?

Yes it did. The influence of media and popular depictions of nuclear war on Reagan is very well documented. His experience of WWII was working on propaganda materials, not exposure to the devastation of war. He was convinced nuclear war was likely civilization-ending, an actual Armageddon. In this he was at odds with the bulk of his administration and US nuclear doctrine. His attitudes and interactions with Gorbachov on these issues are also surprisingly well documented.