Present and Past Active Gerunds (ing/ having + past participle)

1. I’m happy about being your teacher.

When am I happy? Now
When am I your teacher? Now

2. I’m happy about having been your teacher.

When am I happy? Now.
When was I your teacher? Last semester.

3. I was happy about being your teacher last semester.

When was I happy? Last semester.
When was I your teacher? Last semester.

4. I was happy last semester about having been your teacher.

When was I happy? Last semester.
When I was your teacher? Before last semester.