Study is work.
Whether you realise it or not, you're actually paying quite a lot for the privilege of being at Uni. If you're not devoting 50 useful hours a week to your study, you're not taking it seriously and you're probably wasting your time and your money. Lecturers can't and won't force you to learn the material. Their job is to present it in such a way that you can learn it yourself. In other words, university education is different from school.