It is an important step to be prepared to revisit lessons and see how they look now you know more. The way that the Microsoft Mashup Engine processes data, it all comes back to the way that M queries are structured. It also helps to remember that the Query Editor is more about previewing your data rather than executing.
Context in DAX is something that you will likely revisit throughout your Career with Power BI. Let’s have a look at just how Context is something that you have to think about in Power BI, especially when we remember that as an amazing Power BI Developer you’ll want to make sure people are able to build additional report content. So this can add another layer to Context.