From personal experience, this is the most important thing. There will be days you will keep asking yourself what significance a little thing that you're doing that particular moment has on the grand scheme of things. The reality is that such little things compound over time. The most important thing is to keep persisting. Early on, you will feel like quitting and jumping onto the next big idea/thing, but only with persistence any of them will become fruitful. After you work on a few projects you will be able to interpret the early positive and negative signs better.