I may get dragged for this but im one of "those people" who cringes at the use of 'retard' to describe a mistake or something that doesn't make sense, or hard.
there are people who are actually mentally retarded, and to equate their existence with bad mistakes, fucked up decisions, hard or things that don't make sense is weird to me. Its also a great time to state that my teaching degree is also in both finance(general) and teaching students with disabilities and special needs.