One of the easiest things in life is to become complacent with who you are, based on the logic that you’re better/faster/harder working/etc. than those around you. That is the quickest route to mediocrity.
Be your own standard.
Set the bar for yourself high. Identify & understand what you believe is: a good way to live, the proper amount of effort, the best way to do something, what greatness looks like, etc. and let that belief guide your morale, behavior, ethics and ambitions. Do not let the person to your right or left have the power over you to make you average.