every night

What she means: why in 5x04 did past!Dean say to future!Dean "You mean you're gonna feed your friends into a meat grinder? Cas too?" Three episodes earlier Dean told Zachariah "I learned that from my friend Cas" so at this point he already considered Cas to be his friend. So why was he not grouped with the others when past!Dean said that? Why did past!Dean choose to separate those two for future!Dean? Is it because he knew that to future!Dean there was a difference between sacrificing his friends and sacrificing Cas? Did past!Dean pick up on the significance of their relationship during the days he spent in that timeline? Did he want future!Dean to know that he knew? Could he just read himself well enough to know that Cas was more than a friend to future!Dean? Did past!Dean already know that his feelings for his Cas were different than his feelings for his friends and knew that future!Dean felt the same?