“What he could do he did.” How does this statement relate to our lives?
I think what the teacher meant is, "How does that statement relate to your life?" This is something you need to answer for yourself. I cannot relate it to your life.
You might be able to relate to it better if you changed the sentence to the first person — "What I could do, I did." What would that mean in terms of your life?
I hope this helps. "What I could do, I did." Thanks for asking.