To be successful leaders, activists must also be well-informed. Better known as the school of hard knocks, it is the most painful way to learn anything, though I can't deny that this school teaches its lessons well. Its drawback, however, is that by the time you graduate if, indeed, you ever graduate, you're too old to go to work. Students who study only at this school learn things only the hard way. No matter how diligent a student you are of the school of hard knocks, you cannot learn by first-hand experience everything you should know.
Careful observation is invaluable to anyone in any field, from sports to science to politics.
But, again, you cannot be everywhere, and everyone's individual power of observation is necessarily limited. You can learn from them all by reading their works and books about them. In politics, it is not enough to know what's right. To succeed, your command of a subject must be so secure that you can persuade people you are right. And then you must activate them.