Both, and dumb luck factors in more than most of us want to admit.

I worked hard to get where I am in life, but I had some privilege to begin with (as a middle class male heterosexual WASP I wasn't trapped in the cycle of poverty, and had adequate access to education and health care, and had close to zero discrimination to cope with, etc). That's dumb luck. Along the way I stumbled into a profession that aligns unusually well with my innate talents and interests -- dumb luck again; such a thing might not even have existed for some combinations of ability and interest.

These combined to give me a sense of plausible forward movement most of the time, hence, hope and encouragement, despite a number of huge personal setbacks (more dumb luck, both good and bad).

This is really a question about determinism when you unpack it. Given my strengths and weaknesses and the random socioeconomic and family milieu I was born into, and the particular interactions I was obliged to have (parents, siblings, classmates, colleagues, wives, children, etc) is it more or less inevitable that I am where I am today? How much can I truly credit my personal virtues, such as they are? It's a largely unanswerable question, but one thing I know for sure is that most people give themselves way too much credit and have way to little epistemological humility about their accomplishments.