Ask HN: What made you join that startup?

What were those one or two major factors that stood out for you when you decided to take on the risk of joining a startup which was yet to gain traction and prove product market fit. I am trying to understand what motivates someone to throw away their stable job with a well defined career and financial path at a big FAANG like company and join a startup as an early employee. Please feel free to share any personal experiences and/or anecdotes.