So I figured out a few things since posting this thread:

1. I have gotten away with only knowing a few parts of the whole pie in all seven years of my experience in this field.

2. I have been able to be successful so far, in knowing just a few parts.

3. I should know ALL parts of the whole pie at this stage, but I do not. I think my company believes that I know all parts, when I do not. I've been able to fake my way through.

4. This is why I am freaking out about potential failure. I am afraid that now I am going to be in front of clients, presenting in front of my colleagues, that the truth will be discovered.

5. My solution? Is to do more tutorials tomorrow on the aspects I don't know as well... and as much as I can either throughout the week, or on the weekends.

6. I shouldn't feel too too bad about not knowing the whole pie, because I am largely self-taught & I've barely had the chance to work on a team that has similar knowledge.

7. BUT I am still very scared of failure and of being found out.

ARGH. I cannot believe I've made it as far as I have, or that I even landed this job to begin with. And this is why I feel I don't deserve the title "senior" when I hardly know all pieces of the whole pie! UGH.