Watching live comedy (or Computer Science lectures) is not the same as watching television. The audience is an integral part of the show. If you're engaged and enthusiastic, the performers pick up on your energy. The result is a completely different lecture.
Your Computer Science lecturers and tutors are not robots! They're humans who wonder if they're having an impact. They love nothing more than engaged and enthusiastic students. If you particularly enjoyed a subject, don't hesitate to say thanks!
Take the time to get to know your lecturers and tutors. They all have super cool hobbies and backstories. (They also swear more and tell dirtier jokes when they're off-stage.)
Make a little more effort and take an active approach to your studies. You'll learn so much more!