There are two reasons why we "need to identify a few broad categories (i.e., career, family, health)" rather than start with specific goals.
First, we should always remember the main goals of our life. But since people cannot keep in mind more than 7 to 10 things simultaneously, these 7 to 10 main goals inevitably incorporate many specific goals and therefore become broad categories or activities. For example, you may incorporate such specific goals like good relationships with friends, colleagues, superiors and relatives in one activity called "Relationships" in order to diminish the total number of activities so that you can keep all them in your mind.
Please notice that activities or broad categories are not the things that are on your to-do list. They are too broad for that. In our to-do list we usually write the specific goals that follow from our main activities. For example, when you compose your to-do list for a day, you may, keeping in mind the main activity relationships, write on the to-do list that you should invite your friend to dinner or send your aunt a birthday card.
Although it is useful to have a to-do list, most modern time management gurus stress that always keeping your main activities in your mind is much more important. Why? Because it makes you more flexible and allows you to adjust your behavior quickly to the current situation without sacrificing your main goals.
This is the second reason why we should keep in mind a few main activities rather than specific goals. For example, let us assume that you jog for health but do not especially like jogging. If you are on a business trip and find yourself in an area or on a schedule not conducive to jogging, your first impulse might be to delay the jogging until you return home. But if you keep in mind the broader category of health or physical fitness, you will start to think of what you can do for your health instead of jogging and simply do some aerobic exercises in your hotel.
There are advantages to formulating broad categories of main activities rather than long to-do lists and specific goals. As Stephen Covey writes "Basing our happiness on our ability to control everything is futile". So we have to look for opportunities to do our main activities, always keeping them in mind: "Effective people are not problem-minded; they're opportunity-minded. They feed opportunities and starve problems."(Stephen Covey).
Peter Drucker actually also stresses that to identify your main activities is more important than to make long-term, detailed plans or as to-do list: "Planning should tell you only which opportunities are the right ones for you and which are the wrong ones. I always fell into the right slots."
We see that our main activities are quite different from the things in the to-do list. As was discussed earlier we need an external help - either a person or an application - to manage and remember our main activities because people have no reliable sense of time and tend to forget things that have no external stimulus. There are many applications that help you compose to-do lists but I could not find one which manages more important list, the list of your activities. Since I am a programmer I designed the application Activities and Priorities, which manages the main activity list and reminds you of your current main goals.
I don't mean that you should not compose to-do lists. Simply I believe that Activities and Priorities makes long-term and detailed to-do list rather obsolete because Activities and Priorities reminds you about your main goals. Here I agree with time manager expert Hillary Rettig, who writes in her article for Microsoft "ChannelBiz": "As the number of items on your to-do list grows, your ability to accomplish your goals diminishes. (Having a long to-do list will also, ironically, make the task of time management itself take longer.) Your goal should be to come up with a daily list of fewer than ten or, better yet, five important tasks".
Since your to-do list thus becomes short and does not include the distant future, you can simply write it on a sheet of paper. Later in this guide I will show you how to make a convenient to-do list for a week from an ordinary sheet of paper (this is not my idea but I like it very much and have been using for years).
"What is the most important thing I can be doing with my time right now?" (Alan Lakein's crucial question)
"A doing the right thing is more important than doing things right. Doing the right thing is effectiveness; doing things right is efficiency. Focus first on effectiveness (identifying what is the right thing to do)." (Peter Drucker)
"It is more important to know where you are going than how to get there quickly. Do not mistake activity for achievement." (Mabel Newcomber)
"Let us not become weary in doing good, for at the proper time we will reap a harvest if we do not give up." (Galatians 6:9).
"Basing our happiness on our ability to control everything is futile." (Stephen Covey)
"Planning should tell you only which opportunities are the right ones for you and which are the wrong ones. I always fell into the right slots." (Peter Drucker)
"Effective people are not problem-minded; they're opportunity-minded. They feed opportunities and starve problems." (Stephen Covey)
"Personal leadership is not a singular experience. It is, rather, the ongoing process of keeping your vision and values before you and aligning your life to be congruent with those most important things." (Stephen Covey)