That means if there's a community for the topic you are writing about, you should post in that community. Use OCD only if there's no community for the topic.

Also does it mean that all I have ever posted in the OCD community,I shouldn't have?

I'm not going to go through one year of posting to analyze each post of yours, you can get familiar with the communities we have on Hive and decide if there's a niche community for the topics you are usually posting about. It's a good way to get familiar with the existing niche communities we have on Hive.