Colleague: I need a change made to this project, when will you have some free time?
Me: Next year
Colleague:....
I love the look on peoples face when I give an answer like this. It's a mix horror and confusion and It's not even a lie.
Obviously they actually meant to ask when will I be willing to push my other work aside and do theirs at the expense of my current project. Of course that doesn't sound very polite.