Belzelbub
Contributor
My thoughts exactly upon reading the title of the thread.Looks like LD has a new login.
Now, just to give the poster the benefit of the doubt by assuming this is a genuine question, here are my thoughts on it.
Certification is required to dive with many (most/all?) dive operators. Most (apparently not all) dive shops will require certifications to get fills. I will say that I've gotten fills before from dive shops that didn't ask for my cert. Some knew me, others didn't. So, if diving private boats, etc. then certification may not be required.
Training, however, is a real good idea. Yes, it is possible to be self taught. It's possible to have a real good grasp of the principles of diving without professional training. Based on some of the concepts mentioned by the OP, I don't think that's the case here. There is value in having a good instructor providing instruction and critique.