Have you ever had a thing you knew you had to do, at no specific time, perhaps before some seemingly-distant limit (4 months from now, 6 months from now, etc)?
Have you ever totally forgotten about it for a while?
Have you ever then had someone casually remind you of it? And in that instant, got a sense of panic? Oh crap, how long has it been? How much time is there left to do it? I better get on it right now before I totally forget again.
So you got up and immediately went to do it?
And the person who reminded you went, "Oh no no, you don't have to do it right now!"
To which you could only respond, "Yes. Yes, I do have to do it right now. If I don't do it now, I never will." ?