Constructive comparison is acceptable, when it is for self-improvement, leading to a "I can do" mlndset. Distructructive comparison is not acceptable, it leaves you feeling less than, and "I can't do that mindset". Ultimately, we decide which, according to Desiderata, ...If you compare yourself with others, you may become vain or bitter, for always there will be greater and lesser persons than yourself... Find your best way, not your better than way!