Cars break down.
Lawnmowers break down.
Computers break down.
Immune systems break down.
Companies break down.
Governments break down.
So, yeah, of course your best habits are going to break down. Expect it. What doesn't break? Sometimes you permanently achieve a new level, and that's great.
But the real trick is knowing that even if things break down, you can get them running again reasonably quickly.