On occasion I omit commas. On occasion, I use them. (The more you know about English, the less you're likely to think there are unbreakable "rules" for a lot of these things.)
Bill WalshYour enthusiasm becomes their enthusiasm; your lukewarm presentation becomes their lukewarm interest in what you're offering.
Bill WalshOne of the common traits of outstanding performers-coaches, athletes, managers, sales representatives, executives, and others who face a daily up/down, win/lose accounting system-is that a rejection, that is, defeat, is quickly forgotten, replaced eagerly by pursuit of a new order, client, or opponent.
Bill Walsh