One. Vegans have the same capability of changing a lightbulb as non-vegans.
They still haven't figured out how to screw in the lightbulb
None. They'll just stand in the dark talking about how good the old one was.
Two. One to change it and one to put some chips with it.
Two. One to hold the bulb, and one to drink until the room starts spinning.
When you ask them "Are you a vegan?" and they say "Yes".
She says "Nothing, just wanted to tell you I'm vegan."
Non-prophet.