Have you noticed how frustrating it is to look for love and approval outside of yourself? The mind tells us that the answer id outside in the world ; when we get the job or find the perfect partner or have the right amount of money we will be "happy".
This is a lie. Even in Tai Chi practice the mind does this. It says when you understand the postures , when you feel the energy, when you are a success...but I have noticed that none of these things completely satisfy the mind . It's like the Greek story about the mermaids who lured and shipwrecked the sailors on the rocks - the mind keeps luring us with stories of what will make us happy and fulfilled.
With a practice that quietens the mind we begin to realise that the fulfillment is here already. You're already whole and complete. This does not lead to becoming lethargic and having a 'couldn't care less' attitude. Paradoxically, you become more fully present and engaged in everything you do.