You're correct in the metaphoric sense. From what I've gathered, Wilson's first version was intended literally as a bar-closing song. Coincidentally, his wife was pregnant around that time with their first child, and at some point he realized the song could have a dual meaning. Apparently he revised or altered some lyrics to encompass that, while maintaining the initial theme.
For a short time I attempted to listen to college radio again. All they played was Wolfgang Press and G Love ASS- It was a running joke I switched it off haven't attempted to go back since.
These fall into the “drinking problem” category. Ironically, the music in each inspires maybe having one more drink (but just one!) … it’ll be different 2-morrow.