Success... Can I have some?

I aspire to be successful. You aspire to be successful. Everyone does. 

What even is 'being successful'?

Will I reach a point in my career and say 'I am now successful', or will I always want more? 

Will I have kids, get married and have a mortgage and be 'successful'?

Does success mean different things to different people, or is success a state-of-mind we reach when we feel content with what we've achieved and are surrounded by? 

Is success an unrealistic expectation we set ourselves only to end in disappointment when we never fulfil it? 

What does it mean to you? 

Can it be achieved?