That's sweet of you to think that way, but a good friend would want you to share something that upsets you. Even if they can't help, they can offer you their love and support.
They might give advice, I guess. And even if they don't, voicing the problem can give perspective, as a remainder it is not 'end of the world' after all.
The answer is simple. Take a Valium and forget that you ever nipped in to the cooking sherry and twirled about coquettishly with the mailman! OH! I blame UPS
It depends on who you share with, how often you share and what exactly is the nature of the problem. Also, are you there for the other person when they're laid low? I think friends come in different grades of intensity. Some I can have a nice evening with, shoot the breeze, then go home and not see them for a while, but their good nature has lifted me out of a funk without having to have deep, involved discussions about why I feel like a bag of ****. Others, I hang out with more often, but know that they're not great with feelings, either because they're afraid of them or are dealing with too many of their own, but are great with practical problems (I'm having a real problem finding a therapist, I don't know how to tell my mother I don't want her to come for an entire week) Others will listen to my deepest anxieties about the meaning of life and my place in the grand scheme of things, but only if it's a once-in-a-while thing. The above friends are the ones where I've felt worse for having brought someone else down.
A few you can call anytime and really get into it over and over again, but these are few and far between. They're the ones who I don't feel guilty about sharing a problem. A few very rare friends in my life have been able to do all of the above things. And I also try to be present to their troubles, because sitting in a stew of my own difficulties for too long is not healthy. I don't always succeed, because sometimes my nose is planted too firmly in my own navel, but if I realize it, I try to do better by my friend the next time.
Like good wine, different friends are appropriate for different occasions. Provided they're not users or backstabbers, I can never have too many real time friends in a world where friendship has been reduced in many cases to following someone's post on Facebook.
It's doubled for one reason or other.