Gripe of the Overwhelmed

(Intentionally vague, and to be ignored. Apologies)

Yes, today's meeting was an informal one...
But why do I still feel like I entered the room with insufficient preparations, especially when fielded with questions I couldn't answer?
Can I really accept this new challenge, and live up to expectations, when I have so little background in what's required?
Why do I allow myself to get delegated these things?
Have I been thrown a fish that's too large for me to handle?

What did I just get into ?!?