I found this via google. Not sure how true it is, but it helps to make the point that things need to be repeated for us to digest them, making them apart of our lives.
On average, it takes more than 2 months before a new behavior becomes automatic — 66 days to be exact. And how long it takes a new habit to form can vary widely depending on the behavior, the person, and the circumstances. In Lally's study, it took anywhere from 18 days to 254 days for people to form a new habit.
But you are to proclaim things consistent with sound teaching. Titus 2:1
Proclaim is something we are to do continually – We also need to continually be doers of the Word that we hear.
But be doers of the word and not hearers only, deceiving yourselves. James 1:22