what people think of you?
Re: when does it matter
when u value their opinion 
Re: when does it matter
Can depend upon what is at stake (job, relationships, etc) and how much that matters to you.
Also when you base your self-worth on how others perceive you.....although sometimes considering people's views can even be beneficial.
Re: when does it matter
most of the time it actually does........
Re: when does it matter
never now! pehle kabhi thay hum aisay