Achieving self is the term used in positive psychology. Achieving self can be improved by doing some worth activities such as vocational and avocational activities. These activities improve the self-esteem and self-confidence of a person.
There are some tips to improve self-achievement:
First to select a goal that should be worth living.
Attempting to reconvene with them and maybe they will come around. Try making time to hang out and do fun stuff with them. Also people can have multiple best friends and when he said that in the store he could have said it out of impulse in the situation so don't take it to personal.