Setting goals - and one recommended book to read

I believe that one important part regarding investing is to set a clear goal for yourself. I did so somewhat more than ten years ago. Then I was in my early 30's, and though fairly successful in my career there was still no way that I would be able to have financial independence in the near future. Still, I made some bold career moves and even more importantly, I set a very clear goal regarding my financial status in the future.

I did this after quite many months of thinking of how to formulate the goal, and inspired by the classical book 'Think and grow rich' by Napoleon Hill. Kids, read it when you get old enough. The rich part is not really important for me, I translate it to free (free in time to do what you want with your most precious and limited resource: time). Today I do not remember much of the book's content, but one thing that it inspired me to do was to think about my goal EVERY day during that time period I set my goal for.
What I did was that I calculated roughly what I would need in assets to live a good (but not fancy according to my own standards) life and not have to work for the rest of my life (i.e. freeing up time for myself). I came (then) to the conclusion and goal that I wanted to have 2 MUSD in assets (in the more traditional accounting-style definition) and being completely debt-free. The assets should be distributed as 2/3 for investable assets (cash-generating assets) and 1/3 for housing (cash-consuming 'asset'). The starting point was around 0,1 MUSD in assets. I set a very clear time-limit on that goal: to reach this by June 30th 2013. I failed.

However, I came a long way. Today (one year late) I have reached more than 2/3 of my goal in terms of assets, and as inflation has been much lower than I anticipated back then, I am in a very favourable position regarding my time. I will write more about this in upcoming posts.

I am now considering a new major goal in my life, but I am not sure yet what it will be. I am starting to lean towards becoming a 'mid-tier millionaire' 20 years from now (i.e. having investable assets of 5 MUSD or more by June 30th 2034) and to be completely debt-free. This is fairly ambitious, so I am still considering how realistic it is, and what it would take for me to be able to achieve it in such a time period. The key thing I am considering is how the plan should look where I balance/optimize between additional definite positive cash-flow (i.e. having a job or similar), spend my time on improving expected return on my investments and having more free time, all while having a financial independence with a fair margin of safety.