I recently went through something that was not good, that made me feel generally shitty. And even worse, though it shouldn't have mattered, I was worried about what a good friend would think.
But I needed to spill, so I did. Not only was my friend understanding, but also supportive and nonjudgmental.
This was kind of an epiphany moment for me. Everyone has friends, everyone has people that play a senior role in their life, but how many people are right behind you for everything? Who has your back? If they aren't supportive of you as much as possible, and willing to understand you, then they shouldn't be at the top of your friendship list. The sad thing is that I even know married people who don't exhibit that kind of support in friendship. I should know, because I was one of them at one time. That's not a regret, but at least I have that awareness now.
Never underestimate the impact you can have just by listening.