You won’t believe it, but talking to a good friend who hasn’t studied marketing or data science is actually a good idea!

Talking to somebody completely unrelated in terms of content (e.g., friends, your parents) ensures that your ideas are rooted in real life, and are interesting. Ask your friends/parents to be tough on you: they’re not supposed to like the topic because they like you, but because they actually understand the importance of what you are trying to study.