I think there are times when I dismiss criticism because of the source or the delivery, when I shouldn't necessarily do so. On the other hand, there are times when I take criticism far too seriously when it is not warranted and maybe even has more to do with the other person's circumstances or style than me personally. It was a revelation to me a few years ago that someone's negative (or positive) opinion of me didn't necessarily make that pronouncement true. It was simply a snapshot of their perspective, with the information they have at that particular point in their and my lives and communicated in the way that made sense to them at the time.
For example, I have a good friend whose teaching and musical ability I respect greatly, although his people skills leave much to be desired. He came to visit and shared some music that his groups had just played at a show and suggested we try it out together. Later, he said quite candidly that he really prefers playing alone and gets very little enjoyment out of playing with others, using our session of playing earlier that night as an example. In the past, I would have taken it to mean that I simply wasn't at a level of playing that he found stimulating or enjoyable, as I frequently see him playing with others and enjoying it. I realized though that he was just giving me his unfiltered opinion, maybe even without that extra statement in there, and even if that extra implication was there, he didn't mean it unkindly. It was just a fact. If I were to offer my unfiltered opinion of some of our interactions, it wouldn't sound flattering either, even though I care very much about him.
In some ways, it's been very freeing to realize that a lot of the time, I probably do read in more than is intended and I need to actually check and see what they did mean. It also is freeing to realize that some people simply do not have enough information to work with, or what they are saying is not really a reflection of my own value or competency. I think I am already fairly critical of myself in some ways, and so it is a very vulnerable feeling to have someone lay out my faults (particularly publicly) when I am not expecting it. That is why processing time and delivery matter a lot for me to be able to believe that their intent is good-natured and constructive.