One of the major tenants of GTD is capturing thoughts as they occur.
Warning: if you are new to GTD, stop reading now!
However, there are times when this is superseded by a higher law: the law of love.
For instance . . .
Your significant other is proposing marriage when you remember you forgot to buy raisins at the grocery store. What should you do? Pull out your planner and make a note? NOT!
I have been guilty of this (not quite that bad, but still).
So how do you make the determination? I think it should be rare because most of the time capturing todos as they occur is a wonderful and freeing practice. But sometimes significant people (or significant activities) in your life need total and undivided attention. At those times, I feel you need to suspend your practice of capturing todos. The bottom line is that you want to weigh the significance of the todo against the significance of the moment.
So what do you do when a todo comes to mind in the middle of something very important? I pray something like this, “God please bring this back to my mind when I need to remember it” (special thanks to my friend Chris Cole for this prayer).