We all have goals that we work towards. We all have things we want to accomplish and projects that we work on throughout our lives. In the hope that this will give us a feeling of completion and satisfaction, we struggle on, never really reaching the contentment we so desperately seek.
The truth of the matter is that satisfaction is something fleeting. It is something that can be felt when reaching a goal that we worked towards for a while, but it is not something that can be maintained and preserved. Rather, we need to set new goals and venture on to new frontiers.
So this leaves us with the realisation that self development (which in fact is nothing else than setting goals and achieving them) does make sense when looking for fulfilment in life, but not because of the goals that we set out to reach. Instead, it is the long and tedious process of trying to reach that goal which brings the fulfilment. Self development is the ability to fall in love with the process instead of the result. If one manages to reach this form of self development, happiness in life is guaranteed.