I was a lefty who played a righty upside down for about 9 years. For whatever reason I tried but failed early on to switch to true lefty. The thing that made me switch for good was wanting to bring the funk (slapping) and finding my fingers were all out of position...went out and bought a lefty bass right away and didn't look back. Making the switch turned out to be less of a hassle than I'd feared...guess my dexterity/technique after 9 years of playing made it easier than my earlier fail.