5d mkiii lack of built-in flash

i'm currently on a 60d and have been toying with the idea of going ff with the new 5d mkiii. newb question, does the lack of a built in flash mean that i'd always have to use an external flash for indoor night shots? i understand that one of the benefits of going full frame is making full use of lenses like the 35 1.4L (which i already have), and the 50 1.2L, and that these lenses are good for night shots, but will i be finding myself needing the external flash much?

thanks!