When we want to make a change, our energy and motivation are highest at the moment of commitment. Unfortunately it then subsides as we are tested through familiar patterns.
The sentiment that “100% is easier than 99%” can be a great way to clear these initial hurdles when a commitment is made. It means that you aren’t provided yourself allowances to fall back to your normal behaviour in those early days.
Keep in mind this is not the same as going “cold turkey”. Cold turkey usually comes from a position of resistance, where you are trying to resist a temptation as much as possible. “100% is easier than 99%” comes from a position of empowerment, where you know that making allowances for the “1%” is a slippery slope, and you are choosing to commit 100% to the lifestyle you wish to live.