You can do anything, but not everything. If a task isn't getting done, then either you have decided (consciously or unconsciously) that something else is more important, or you are avoiding the task for some reason.
If a task isn't getting done, then
(a) Decide if you care. Maybe it really wasn't that important after all.
(b) Decide why it isn't getting done: is there an obstacle that you haven't consciously considered, and
(c) Decide what else you're going to not do in order to make room in your schedule.
(c) in particular depends on your personal values. Deciding to not watch TV is far different from deciding to not play with your son or not visit the gym as often.
Katherine