I will give you a modified version of my motivation mantra. Instead of "The motivation is out there."... I will say, "The route is out there." ... Meaning, that you only have to Begin an alternate route far enough that it's more trouble to return to the original route and by that time you're already on an alternate route. Once you're on that alternate route you should be presented with differences in traffic patterns scenery and specifics that will make it entertaining And enjoyable enough. Don't forget those alternate routes can be modified as well.

I realized that in Manhattan you have fewer alternatives but they are there. Perhaps the tomfoolery involved Is as simple as giving yourself the task Taking a picture of a landmark or location that is not on your regular route. Once you have bicycled there pulled out your phone and taking quick photo you have to get to work so you are already on an alternate route.

(Please excuse any weird typos I'm actually on the Windows laptop slash tablet on the indoor bicycle and the voice to text even crazier than the one on my Google Phone.)