Working by the time you get out of college is a "goal," it is not the definition of success. Many of us go through life chasing "success," or "happiness," without ever defining those terms.
One of my favorite quotes, from Henry David Thoreau, is "I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived. "
In my travels through life, I have found that one usually has either time or money, but not both at the same time. I also learned that of the two, time is more precious.
One's definition of success changes over time. I encourage you to start by trying to define it NOW, so, when you get there, you will know you have arrived. Some things to consider:
1. career - are you driven to be tops in your field? Some people set milestones, like, "by age 30 I will be the area manager." Others are content to stay in the same job, without advancing (such as many police patrol officers), as long as the pay increases over time.
2. family - do you want to have one?
3. financial - I can talk a lot about this, but, learning to handle money is important. Financial success doesn't necessarily mean being wealthy. It could mean having a nice house, being able to pay your bills and invest, ability to handle unforeseen emergency expenses without having to use credit cards, etc.
4. personal - are you happy/content with your life? Do you have time and energy to do the things you want to do?
I encourage you to think about these things!