I once had a discussion with a youngster west of Orga Camp. There was an Orga Warlock inside, and he asked why I just didn´t rush in and killed it. I said I knew where my limit was. At the time, I had just enough histia to deal with one. A warlock is never alone, there would be other orga about that probably would get their lucky hits at me, or worse - trap me while the lock pummeled me with bolts. He told me I was a chicken, and bragged about how he could solo one. Later that same day, I heard he had fallen to one. I guess he failed to take into account all the other orgas...
Waiting outside Orga Camp 2 there are usually many inpatient ones, yelling why we don´t charge, aren´t we going to save the fallens etc...And then many rush in, one at a time of course, only to fall to 15 bolts in the next second. Terribly stupid, and even worse - it makes the rescue harder to do - having even more fallens blocking the entrance. And a healer and/or a fighter less when we DO charge.
I know I can at this moment solo an Orga Wrath in the colio. That doesn´t necessarily mean I can solo one in the wild, with a zillion other things trying to hit me, getting in my way, force me to swing at them and not the Wrath etc. Every situation is different from the next one.
Know where your limit is. Don´t tell everyone you can solo a Zerk when you can´t. Someone will take you up on it, and there might be fallens and a healer that depend on you. Also know how you stand against many different beasties. How much damage can you take from a fury for example, can you approach one on yellow and still be safe? There is nothing wrong in telling others you can´t solo this huge beastie, nothing embarrassing at all. By doing so you show consideration and intelligence, not weakness.