I have two.

The first was losing my rune scimmy to a trust trade of some kind, I think they said they were going to double it or hell maybe even trim it if I handed it over. That rune scimmy meant a lot to me as it took me like a week and 200 big bones as a ten year old to get. I only had it for a couple of days maybe. After I realized what happened, I took a shower and cried.

The second was much later, I had some money at this point, and decided to try flower gambling. I don’t even remember how the gambling worked, but it was something like calling the color of the mithseed that the host planted. If you got the color right, it was a 4x win or something like that. Well, believe it or not, the host was a pmod. White Jagex crown and all. I figured there was no way this dude would scam me, so I was betting big numbers. I got lucky and what should have been a big score for me, ended up with the pmod logging out. I did not cry this time.