I confess, to my shame, I didn’t know this rule. 
I agree, my knowledge of the rules is certainly not an example for others.
I have already voiced this (in previous posts) that Legendry should not be a subject of "deification" as a source of absolute truth. Legendary is rather an indicator of systematicity and persistence (in order to accumulate activity and merit), first of all.
Don't be sad. These mistakes are common, especially since new members don't bother to read the forum rules and remain unaware of many of those important rules. They also don't bother reading Meta appeals threads until one day they are surprised by an incident that happened to them or another member, to discover how negligent they were with their accounts. I also didn't learn about account bans until 2018, even though I've been registered on the forum since March 2015, and I was just as surprised as you are now. I agree, my knowledge of the rules is certainly not an example for others.
I have already voiced this (in previous posts) that Legendry should not be a subject of "deification" as a source of absolute truth. Legendary is rather an indicator of systematicity and persistence (in order to accumulate activity and merit), first of all.
In general, reading the forum rules alone may not be enough. You must spend time reading practical discussions of these rules so that you can fully understand them.