Absolutely. There are a range of definitions for successful, but I think in many ways it's best left as "in the eye of the beholder", in the sense that it's about achieving your own personal threshold. If you build a way of life that is sustainable for yourself and provides you with personal and psychological stability for you and your dependents, and if you feel at least reasonably fulfilled in this, you can call yourself successful.
If you don't think you're doing what you should be, or think you could be doing So Much More, or that you have wasted potential, then maybe you're not successful yet, even if you're doing better on paper than some people who do view themselves as such.
Given how many marriages end up in divorce, and how many more must stick together but create a hostile environment for children, avoiding that should be seen as an achievement too.
