What defines success in life (in a Jewish outlook)?
Well, the Gemara Shabbos 31a says that a person will be given the following six-question test after they die; however, this all assumes the person was God-fearing:
אמר רבא: בשעה שמכניסין אדם לדין, אומרים לו: נשאת ונתת באמונה? קבעת עתים לתורה? עסקת בפו"ר? צפית לישועה? פלפלת בחכמה? הבנת דבר מתוך דבר? ואפ"ה אי יראת ה' היא אוצרו
- Did you do your business with integrity?
- Did you fix times for Torah-study?
- Were you involved in raising children?
- Did you look forward to the Redemption?
- Did you delve into wisdom?
- Were you able to apply one topic to another?
So I'd start with those (I know, I'm giving specifics and not generalities).
Success in life means after you die the honest Wikipedia page about you will read nicely.
I.e. you have a chelek in olam habah because you added to the meaningful goodness of the world in face of adversity.
People who do not have a chelek in olam habah spoilt their Wikipedia page, they did something more negative than they could compensate for and were unable thereafter to find a place in a meaningful world.