What's your plan in 3 years time?

During my annual appraisal, manager asked this question to me...

My mind was thinking, everything seems to be so dynamic.

How could you actually plan for 3 years?
I don't even know what will happen tomorrow other than the fact that I need to finish my task before due date.

Of course, this kind of response will never come out from my mouth, it would be rude and sounded arrogant...