The day after the Superbowl where one experiences an enhanced version of the case of the Mondays
and is hung over, tired, and depressed because all of the major American holidays (Christmas, New Years Eve, and the Superbowl) are over.
"So, what was your favorite commercial from last night?"
"I don't know, man....I don't know, maybe the talking giraffes...I don't know."
"Why the long face?"
"I guess it's Superdull Monday...you know, there's nothing to look forward to for months."