Or at least it might seem so or feel so. What I found out about myself is, that when I am behind my plan, it is really hard for me to get back on track. For example, I wanted to read 10 pages from a book a day, but I am 5 days behind, so now I should read 50 pages to catch up. Which is much more time-consuming than 10 pages.
What helps is not trying to catch up but setting a new plan. I wanted to read 10 pages a day, not to read 10 pages, but to finish by the end of the month. So how many days are left there in a month? And how many pages? Ok, now I only have to read 12 or 15 pages in a day not 50 in one sitting.
In this way, it is much easier to get back on track.