Both book emphasize becoming aware of yourself--your wants (in the case of The On-Purpose Person) and your strengths (in the case of Now, Discover Your Strengths).
In The On-Purpose Person, Kevin McCarthy urges us to create 8 want lists: one list in each of the following areas:
- Physical/Health/Recreation
- Finance/Material Possessions
- Family
- Vocation/Career
- Social/Community
- Spiritual
- Mental/Intellectual
- Other
Plan to write incomplete lists, but keep updating them and adding to them over time.
And then, he suggests, run single-elimination "tournaments" among your various wants--like in tennis or the championship series for basketball and baseball: "play" each want against another; whichever one "wins" as most important then goes up against a similar "winner" from a separate contest. Keep playing your wants against each other until one comes out on top. Then play your remaining wants against each other until you find your second most compelling desire. And your third. And fourth. And so on until you produce as thorough a list of top-priority wants as you can reasonably pursue.
I'm not sure I fully agree with placing your own desires at the center of your life's purpose. But hopefully you have acquired "the mind of Christ" and so your desire is His desire or, rather, His desires are now yours (Psalm 37:4, NIV: "Delight yourself in the LORD and he will give you the desires of your heart"; see also Romans 12:2).
If your desires are right and are good, then it sure seems it should be a good thing if you diligently pursue those items that are at the top of your list for being significant and worthy of pursuit! So, once you know your highest priority wants, you can then evaluate how you're spending our time: are you on-purpose, or off? Are you investing your time in those activities that you have declared are your highest priorities