My colleague was screaming You are stupid to the last drop at another colleague who accidentally formatted her hard disk.
Is there such an expression as stupid to the last drop? Are there differences between stupid to the last drop and stupid?
Maxwell House, a well-known if not well-respected brand of coffee in the US, has (had?) a famous slogan that eventually entered the wider lexicon: Good to the last drop.
While that phrase can be heard in various contexts, I've rarely if ever heard the adjective good swapped out for another, nor am I familiar with the phrase being used without any liquid reference point. (That's not to say that the liquid in question is always coffee -- plenty of oral sex jokes also make use of the slogan.)
Your colleague was intending to humorously intensify the adjective by saying to the last drop, but I wouldn't call that standard usage.
It's quite easy to guess what is the difference- to the last drop put a stress on the durability and means like stubbornly doing something stupid all over again.
Aka People are polluting nature but they are being stupid to the last drop.