When referring to a person, "estimable" means "worthy of esteem." I have had the privilege of being a colleague of Luke's for a number of years. He is incredibly deserving of the Statistical Computing and Graphics Award. I will reflect on Luke's impact on our department's mission, on its research program, and on my own work. When referring to a [generalized] linear model, the meaning of "estimable" is similar. However, it is not a very well-understood topic when it comes to its impact on R procedures. It seems to be viewed by some as a kind of "SAS thing" of no interest in R, and even as something that is not possible to address (that is not the case). I will review the definition of estimability and how it can be assessed in R models, and provide examples.