what does success actually mean?

When I was younger I thought the ultimate goal of my life is to be happy. I continued thinking that till I was a teenager, and someone questioned me “How’d you feed yourself, if you only follow what you love?”. I was stunned at the question but it was just a lesson that our career should include both, what we love and what we get paid for, and the ultimate goal, the intersection of these two sets( in mathematics we learn, the intersection of two sets is the part common to both the sets).