Thank you for having the courage to post about this, and for gracefully taking the criticism here.
I think the biggest lesson here is that, as a new diver, an awful lot of the mechanics of diving are still requiring a great deal of bandwidth. When you add a lot of distractions, important things like navigation, buddy awareness, and gas management can slip. I really believe that new divers should keep their lives simple until things like buoyancy, gas management and situational awareness have become fairly solidly established -- THEN do more challenging dives, or add things like cameras.
And as far as "same day, same ocean" diving goes . . . I think sometimes it's quite hard, as a new diver, to stick to what you have been taught, when you see that no one around you is doing it. I remember being bewildered by people diving without doing any kind of buddy check, when I had been taught this was an important part of diving. I've eventually learned just to be a PITA about it and stop worrying what anybody else thinks, but as a novice, it's hard to have that much conviction. The bottom line is that, especially as a newbie, you should dive with a buddy, and you should do what you need to do to make sure you have one BEFORE you get in the water.