A really, really big part of this is thanks to RStudio, which, when you run a line and write a line will peek into memory to see what the columns in your datafr

A really, really big part of this is thanks to RStudio, which, when you run a line and write a line will peek into memory to see what the columns in your dataframe is and understand the dplyr DSL to help you auto complete what essentially is non-existing variables.