The principle that small, "harmless" things/events/people/actions have a cumulative effect that will ultimately destroy you
In Productivity:
Having 15 tabs open at the same time, checking social media 50x a day, checking your phone every 3 minutes
Eating little snacks, sweets, sugary drinks, booze and a half dozen key bumps because "I don't do it all the time"
In Relationship:
Giving your girl "a little cash here and there" to spend on shoes, hair, cell phone cases, Kylie Jenner lip gloss and scratch tickets
Big things may be unavoidable
Small things ruin you after REPEATED exposure on a LONG timeline (like the bad habits you've had for many years)