Do professors enjoy lecturing?

No, that's not their job. Their job is usually first and foremost to do good research, publish a lot, and bring in a lot of grant money the university or college can take half of. Other requirements of the job include advising graduate students and serving on committees. Teaching is only part of their job, and most of that time is spent preparing for lectures (up to 10 hours or more for a single lecture) and grading. Giving lectures is a very short part of their week, but yes, if they're teaching in the first place it's often something they enjoy. If your professor is sitting there reading from notes, complain. Most people don't need applause to feel like they're doing their job. And not all subjects are easy to discuss; no one cares how you feel about math.