For example, yesterday I had a Mock Trial team meeting. My coach had asked us to come up with any and all key pieces of evidence the Defense and Prosecution needed to bring out. Why didn't I have my list? I was too busy doing freaking AP Environmental Science homework, and Chemistry worksheets.
Another example: I have science olympiad this Saturday at my local college, who always hosts it. I've had a few hours over the past week to prepare for it. Why? Because I have so much homework, I never have enough time to practice my extracurricular activies.