It can be a bit tricky, there are a lot of gotchas, and it's generally hard to debug if you're new to it. I've found it helps to walk through and dig into ever

It can be a bit tricky, there are a lot of gotchas, and it's generally hard to debug if you're new to it. I've found it helps to walk through and dig into everything the notebooks are doing, how the data loaders work, etc. The Fast.ai library does a lot of automagical self-configuration, which can save time if you're experienced with it and know what to expect, but can burn a lot of time when it does something you don't expect, and don't notice it doing that.