I love freedom. One of the freedom I have is to practice, or not to practice. So why do I practice? I sort of know the answer in the past, but it only became crystal clear to me when I woke up this morning, and knew why it isn't so clear to me in the past.

I have practiced the four foundations of mindfulness for years, among other Buddhist practices. All in all, they helped me to understand myself and others better, and made me happier. When the benefit of mindfulness is immediate, that is, my mind is joyful, peaceful, and clear, that is reason enough to continue practice. When mental obstacles are present, mindfulness is weakened or absent,  and my mind is confused; it can only react out of habits when it's confused. Clarity of mind is the key indicator. I can be happy without clarity of mind, but it's better to be happy and be fully aware.

When the conditions are not there, the benefits of practice won't be clear and immediate, so there is no strong motivation to practice. If, however, I'm willing to become fully aware and am not trapped by my mental chatter, it's possible to see what obstacle I'm facing, and change my state of mind for the better. This redirecting of mind to the right thing is called appropriate attention (yoniso-manasikara) in abhidhamma. Whatever I pay attention to, that is my world at that moment. It is important to be aware what I pay attention to, and see what effect it has here and now. Simple, but powerful. I got numerous insights out of it when I did this.