Why does a train at rest only need a little door stopper to keep it in place while a train going 60mph will go through a brick wall?

Simple.

Momentum.

The same applies to our efforts with fat loss. Anyone can put together a 4 day streak, but when the weekend hits and all the sudden we have 17 drinks and 4 burgers from Jack in the Box, there goes our streak, and it takes us another 4 days just to get back in the rhythm. 

Don't make these mistakes. 

Take a lesson from thousands of people who have come before you and set your efforts up in order to create hot streaks. When you do that, you'll see the success you want.