At 25, success might have meant money or status. At 50+, has your definition shifted? What does success mean to you now?
I was never one to look at "success" as a milestone. Success always meant I was employed, and that each career move increased my skills and of course my salary.
Now, at almost 60, I make the salary that my 30 year old son makes. It took me 40 years to get there, and while I am thankful, I wouldn't say that I was really successful. He will have a nice nest-egg for when he retires. I on the other hand will still have to work in some form when I "retire" for my current job.
I will own my life and why I am not sitting on some nice financial cushion, but I also acknowledge that 40+ years of adult life was not kind or gentle to me.
I feel successful now in that my kids are all grown, well-adjusted, and good human beings. I feel like that is my biggest success. I also have positioned myself as a semi-pro musician to earn money doing something that I adore. To me that is success. My career, again, was never the marker for success for me.