It happened a January 24th : an emperor was killed, but nobody weeped in Rome... Maybe calling the man “VENUS” was not a good idea after all.
My local museum has moved him twice and removed his head to be more accurately restored but I still prefer the old exhibit.
Nobody weeped is certainly true for the senate. However, some sources say he was relatively popular amongst some parts of the Roman population. Probably due to the many extravagant games he organised. And of course his father, who was very popular, was certainly not forgotten ! Caligula is often portrayed as a cruel, sadistic monster. When you look at Roman history through modern eyes, I often wonder who were the real monsters in those days. For instance, ‘good guys’ like Titus (Judean wars) and Trajanus (Dacian wars) were responsible for the slaughtering and slavery of thousands and thousands of innocent people including women and children.
He may have been capricious , as Philo implied, but I don't think he was insane. He certainly had heavy duty grudges against the senate and some Julio-Claudians, but after all, nearly his entire immediate family was wiped out. Also, Chaerea was subsequently executed by Claudius. If Caligula were so extremely unpopular, I can't but wonder if Chaerea would not have been pardoned.
Keep the mob happy with free grain and entertainment and the Senate is helpless. Pay the Preatorians large donatives keeps them loyal. Thus the emperor can do whatever he pleases. Doing these does not make him sound insane, just very calculating, cruel and amoral.