As they say, there are two rules in improv: Never say no, and never ask why. When another actor asks 'Why?' or says no to something you're suggesting, then it's very clear that they're putting the onus on you, because they're not comfortable with it themselves.
“Some people carry their hearts in their heads; very many carry their heads in their hearts. The difficulty is to keep them apart, yet both actively working together.”
“We found a way to make things look great to the human eye through the window of a graphical web browser without worrying about what everything looked like under the hood.”