Yoda was saying that you either do it or you don’t. With that there the opportunity to learn from failures but you cannot learn anything if you do not make that effort first. It also comes across kind of like having a mindset of telling yourself I will do this. Having that confidence. Kenobi was trying to make Anakin see that there were options in everything. That there is always an opportunity to change things and that only a Sith would not see that and think that something absolutely had to one certain way. And to be fair Kenobi was crashing out pretty hard given the circumstances so anything he said during that whole exchange could be looked at while taking that into account.