Two things to understand here. First, under federal law age discrimination claims are only possible for employees age 40 and older. Are you at least age 40? If the answer is no then you don't have a good age discrimination claim under federal law. Perhaps you might under state law though. First, while he was expressing an opinion about people of "your generation" it's not clearly harassment based on age. However, if there were a series of insults based on age that might set the stage for a claim of hostile work environment based, which would amount to a type of illegal discrimination based on age.