I am not quite sure why but I freakin love Vrksasana {Tree Pose} and migrate to this pose a lot in my own personal practice. It teaches us patience, it calms and relaxes your mind. and central nervous system, while strengthening the bones of the hips and legs. You will find on some days you are strong and stable, when other days you may be unsteady and weak. This is when you tune into the mind and source to why..One side is always different than the other too, which is always unpredictable... With practice you will find it will improve your balance and state but stay true to a still gaze {drishti} to help guide you (and keep you from falling lol). {YogiTip}