Could be an expansion release, guild drama, random encounter, etc.
Mine would be when I was a newer player doing a Twilight Arbor dungeon run with veterans and I enabled "Plant Mode".
I was the classic Longbow ranger with Stalker who had no idea wtf was going on. We got to the wardens on Leurent's path (up) and it was not going well, I kept going down. The others in my party kept reviving me but in doing so were downed and then killed. The champ probably had about 2% health left when I was the last one standing and I am sweating IRL - mainly nervous that I'm going to get chewed out by the other party members if I can't finish the fight.
One of the party members types "Just spam all your buttons!" so I start clicking anything and everything (yes, was a mouse ability clicker back then... how times have changed).
I don't think I had ever used my elite at that point, mainly because I didn't understand it. I just knew it said something about plants. Ended up clicking Take Root and was instantly felt dread. My character was locked down and I couldn't move as I became enshrouded with plant matter.
As if to further cement the absolute embarrassment that was washing over me, the same party member goes "Plant mode?!".
I seriously considered alt+F4'ing to hide from my shame - only to realize that I wasn't taking any damage anymore... And that there were seed turrets spawning all over as if to save me. They started attacking the Champ and it ticked down another % or so - it was so close to dying!
Then my protective plant shroud disappeared and I was running again, desperately trying to live. However, I was still so low from before I had initially cast the elite that I was quickly downed. Instantly I spammed "Lick Wounds" (As many downs in the open world had taught me).
As I inched closer to death another party members says "OMG It's so close". Fractions of a second before I was about to die my pet starts reviving me - and it happens. One of the slow arching shots of the plant mortar near me lands the final blow on the champion and I revive - I was absolutely stunned.
My party was absolutely ecstatic and kept typing things like "Plant mode ftw" and "Salad mvp". In that moment I felt like I was a seasoned GW2 player just like the rest.
Definitely died to the root attack from the nightmare tree just moments after that though.
Picture of my character roughly around the time
Valid point, good clarification!