One aspect of goals setting often gets overlooked: momentum.
Momentum is a movement of some kind, whether large or small. It's pace does not have to be fast, furious to be effective. Momentum can be a few, gentle steps. We build momentum day by day and after a period we can appreciate the incremental gains and the steady, compound interest accumulating of such consistency. Our momentum will not and cannot be the same from day to day, for so many factors, some of which are outside our control. Some days you will be massively motivated and full of inspiration to do work towards your chosen goals. Other days, it will all seem like a up hill struggle - all the way. And it is days like this, that it is important to do something, however seemingly insignificant to maintain momentum, Or, as Nemo said, "just keep swimming."
Do whatever you can towards your goal to maintain your momentum, and consider yourself successful for just doing that when the going gets particularly tough. Even small movements make a difference practically and psychologically. This is more important than getting things wrong, messing up and not doing your best. As we know, your best is quite relative and will change from day to day depending on context and circumstances.. Maintain your momentum and this will keep you connected to your goal. You will get over a so-so day, with lacklustre performance. The problem kicks in when you stop for too long, because this can encourage you to give up, and the "what's the point" mentality can creep in unawares, taking your off your path.
So move, however slowly, keep moving and keep going. Even if it feels that you are going backwards, you are not. Progress is very rarely a linear, hassle- free, upwards trajectory.
Having an accountably coach is a person who is on your side and one of their roles is to help you keep up this all important momentum. We know what to do mostly, what we need sometimes is someone checking in on us so we hold ourselves accountable to ourselves.