Today is the 75th anniversary of Pearl Harbor. I remember the 50th, because Mom and Dad were visiting at my house. We were watching some commemoration on tv and dad started talking about his experience that day. This was the first time I can remember of him talking about Pearl Harbor. I hadn't known, but he was already in the Army. He had been drafted in October or November, 1941. By December, he was stationed at Camp Joseph T. Robinson in Arkansas. I remember him talking that about that camp before this time - probably because we had some photos of him there.
He said he remembered that he was off base, in town, just casually walking down the street. He came upon an officer who sternly asked him, "Where's your hat, soldier? You're out of uniform! Don't you know there's a war on?" And that is how he found out.
Later I went to the National Archives and found some unit histories that summarized some of the activities of his unit. I also got a copy of his discharge which details his date of entry also. Come to find out, Dad was in the Army from before the war started He was in just a month shy of 4 years. his official date of enlistment was 18 Nov 41 and he was discharged in October 1945 - well after both V-E and V-J days.
Fold3 has a lot of digitized WWII records available for free for a while in recognition of the anniversary. If I can find my notes about his unit I'll look for more records.