Tree pose in yoga- am I off balance because others are? 

It has been a while since I attended a yoga class, and during tree pose, the yoga teacher said the usual that you need to have a focus point, before you do the tree pose. And of course during that balancing pose, there are all these wobbly people. And it made me realize that do these off balance people made me go off balance? Or can I stay focused and be on my balance, because that is where I am? It is a bit like life, fire drills at work, screaming children, unexpected thing with kids. Do I let these things throw me off of my joy and peace in life or do I let these little things bother me and ruin my day? There are reason why the yoga teachers say take your practice off the mat.