Answer:
When you have experience in something, you are always looking forward to do it since you're so good at it, in other words, you are always KEEN to do the activity you are good at, you are basically a pro at it.
Explanation:
A keen teacher and 'experience' are pretty relatable, the teacher is obviously very keen to teach something they have experience in, and experience is like for example a math teacher, who has lots of experience in math.
