I bought this pair on May, and it is now Nov.  I have been wearing this pair for about 6 months, and I need to replace them as the back hill cushion has worn out that I can feel the ground.  It has been comfortable enough that I can walk without much problem.  But I wish it lasted longer.  It is not that I am using it for exercise and I am not on my feet for my job.  So why did it only last less than 6 months?