The biggest mistake is not learning from your past OPSEC mistakes.

You will make mistakes some obvious some not, some me and you might not even realize in years to come but as soon as you acknowledge and aware of it there's very little you can do to fix it as it's good to assume once on the internet the whole world could see but take damage control and come up with alternatives to stop this or the risks involved.

Georg Wilhelm Friedrich Hegel -----“We learn from history that we do not learn from history.” hahahahaha

I quite like this.