I have been using ESC-< or Alt-< to jump to the beginning of the file. After I added ggtags for source navigation, normally it works. But after I press Alt-. to find the declaration/definition of some method/class/variable, pressing ESC-< or Alt-< will instead navigate me back to the previous point from which I pressed Alt-. to navigate to the method or class.
I can still use Alt-g g 1 to go to the beginning of the file. But is there a way to still use ESC-< to go the beginning and assign different binding for ggtags to return to previous position?