"I Gotta Be Me"

The famous Sammy Davis, Jr., song title is safe from my wrath by way of poetic license. How, though, did we come to say such in everyday conversation? "I must . . ." became "I have to . . . ," which dissolved into "I've got to . . . ," which fell to "I got to . . . ," that slid into "I gotta . . . ." I'll be honest; I always believed that "I have to . . ." was fine. Literally, though, what does "I have to . . ." mean? Probably nothing really. Now "I've got . . ." to me is a convoluted processing of "I have . . . ," which is a simple, straightforward indication of possession. "I got . . ." means that I received or picked up, not that I currently possess. Ok, so what is the best grammatical version of "I Gotta Be Me"? A college English teacher once quickly responded to my question: say, "I Must Be Myself." Bad song title, excellent grammar!