There is never enough evidence...

It is really flattering when someone flirts with you. 
Evidence that you are beautiful. Desirable.

It is really energizing when you get the promotion.
Evidence that you are valued. Worthy.

It feels really great to get something new.
Evidence that you are successful. Status.

However, no matter how good it feels in the moment, there is never enough external evidence to prove to ourselves we are enough.  And we've seen enough cautionary tales of people who follow the path of looking for more and more and more to know where it leads.

Yet if you don't do the work to seek that which is not dependent on external evidence for joy, peace and contentment, you will fall for the external every time.