Keep in mind that many departments have so-called "weed out" classes designed to test your persistence and fortitude. Engineering is (in)famous for that as is p

Keep in mind that many departments have so-called "weed out" classes designed to test your persistence and fortitude. Engineering is (in)famous for that as is pre-med - as both are disciplines featuring challenging working environments. They need a way to test whether you can "hack it" at the job or whether your slot should be made available for somebody else who can. We can discuss whether this is the most effective way to make such an evaluation, but oftentimes this is what's being done.