Personality is your philosophical ideas, political ideas, economic ideas, your lifestyle, your interests, things you like, your culture, things you dislike, how you behave, what you do, your spiritual/religious ideas, etc.

None of these things are light topics OP. Unless you choose to be nihilistic and say that culture does't matter, culture matters a great deal. OP maybe you think that your interests which define your personality are unsubstantial. In that case you should try and do what you are really interested in and genuinely care about. Be true to thyself. If you are not sure what you really want, try and find it.

I think I've found my calling, and it is what I do most of the time. However, there is still maybe things I could do which are significant and different. Maybe that in addition to what I am already passionate about would make me happy. Or, and this I can't imagine, in the future I will find a different passion and no longer be passionate about what I care about now.