i had a few questions regarding momentum discipline,

so, i made an observation. the more i am disciplined in a task, the more easy it is to continue doing it. the less discipllined i am the more difficult it is to get back to it. its like Newton's law of motion.

for example, last week i had one efficient day. Next day i decided to watch a movie and then boom ..... i didnt do a single thing my entire week.

how do i make sure that i always maintain a momentum?