To know when you have become successful is different for everyone but for me its a moving goal post.
I like to breakdown my goals with in SFI and make them smaller and achievable each day. At the end of the day if I have meet my goals I can say I was successful.
Each little goal will add up to a main goal for the week or month and I can see yes I have achieved what I wanted and therefore I am successful. So it depends on what you consider successful - wealth, goals,etc
