What was once referred to on the MAPS mail list as Macho ingestion syndrome: The desire to prove yourself by taking an inordinately large dose of psychedelics. The object of macho ingestion is not to have fun, but to "push personal boundaries" and prove that you can manage to hang on to sanity under a dose that would surely make lesser mortals wig out. The actual experience itself is likely to introspective and terrifying, perhaps even physically unpleasant because of a high body load. But at least you get something to brag about.
As the word macho would imply, this seems to to be mostly a male preoccupation.