What should my essay topic be?

In case you don’t know, this is the prompt: “Describe an experience you have had, a person who has influenced you, or an obstacle you have overcome. Explain why this is meaningful to you.”

I was initially going to write about how while I was traveling in France over the summer, I stopped a con family from stealing this beggar’s puppy. This was a huge deal for me because I’m really not an assertive person, and I surprised even myself when I spoke up. I was going to write about how it taught me that we are all human, and it’s really beautiful how people from different countries can cross cultural and language barriers to communicate and unite with each other.

One problem: I wasn’t sure if the purpose of the essay was to focus on your academics/ECs, in which case I would write about a volunteer activity I did last year that got me really involved in my city’s government.

Which essay topic should I go with?

anyone? Also, would the puppy thing be a good fit for the Harvard supplement? I was thinking about writing about why I was interested in my major (it’s not very obvious from the rest of my application) but then I realized I might be able to reuse my National Merit essay.