1. Because this might happen:
2. Because your brain will function at a higher cognitive level. In other words, you’ll get smarter.
3. Because it’s highly enjoyable – especially the more you do it. The more you read, the more discriminating you become at making good reading choices, and the more adept you become at reading well.
Here’s how to do some disciplined reading: Why Read Books at All? by Jeffry C. Davis