One day you are happy with what you have got.
You are working hard every day. You are content. You are fulfilled.
The next day you meet someone doing way better than you.
Would that hinder your contentment and happiness?
While your grass was green all through, would you be affected by the existence of supposedly greener grass?
If the answer is yes, here is a question to ask.
Did the greener side always exist and you got to know about it just now?
Or did it come up after you?
The grass has been and always will be greener on the other side.
Then how is fighting for the greener grass even worth it?