How much should you care about what other people think of you?
The answer that jumps to mind is probably, "Not at all!" but I think it's more complicated than that.
I believe in order to improve as a person, I need feedback from other people. I don't know everything, but I can learn from different people with different perspectives who are likely to see things about me I may have missed. I can't just automatically dismiss their ideas. For all I know, they could be right. So in that respect, I should care about what other people think of me.
But, of course, that wears me down pretty quickly. I can't please everyone, so I am setting myself up for failure. At its most extreme, this would mean giving up my free will and allowing other people to dictate my actions. Also, other people aren't perfect, either; they could be wrong. In that respect, I should not care about what other people think of me.
Clearly, there has to be a middle path here. But how do I make the distinction? How do I pick and choose which feedback to accept and which to reject?
Answer: The short answer is . . . ha. Advice joke.
If the primary question of life is, "Why?," the primary question of living is, "How?" - and yours is just a rephrasing of this second question. People spend their entire lives trying to answer it, from when we throw our bowls on the floor as toddlers to when we try to figure out whether getting dumped means we're not worthy of love.
Social feedback is necessary, yes. And there does come a point where you have to tune it out and just live. And, yes, it's complicated, because it forces us to weigh not just what people say, but also who is saying it, what their motives are, what aspect of us they're commenting on, and at what stage of our lives. Oh, and how many people seem to agree with them, and what weight their opinions carry. It's a wonder we leave our homes.
What makes these calculations possible is your baseline: you. Your sense of self serves as the security fence between appropriate, useful feedback and the free-will-eroding kind.
That's why a teenager - with sense of self a work in progress - can feel an existential threat in a mean-girl comment an adult would laugh off. When you have a no-wishful-thinking grasp of your own strengths, weaknesses, preferences, goals, work ethic, and nonnegotiable limits for how much crap you're willing to take, comments arrive in perspective.
Instead of weighing how much to care about what others say, consider putting your mental energy right now into that baseline. What are you good at, bad at, useful for? What do you enjoy doing, who puts you at ease, what goals animate you? What are you willing to do, change, or sacrifice to make someone else happy - and how far is too far?
Sometimes, these answers await us in solitude, through immersion in our thoughts, comforts, and experiences. Sometimes, though, we find them in others - people who bring out our least self-conscious selves. Either way: Find that, find you, find peace.