I think all the Lannisters are batshit insane due to lead poisoning
So Casterly Rock is a great big castle on top of a giant gold/silver mine. Gold and silver mines are notoriously absolutely packed with lead. Symptoms of lead poisoning include things like aggression, paranoia, delusions, etc.
All the Lannisters are vain psychopaths because they spent their formative years breathing lead dust
u/EmptyMirror5653 — 6 days ago