Overcoming Inertia is such a hard thing. Not only does it impact physical options, but our thoughts, too!
The biggest excuse is I'll start tomorrow, or do it a new year's resoluition or whatever. You don't need to have a marker to start, or change anything.
Just overcome inertia and do it. I tell myself this all the time, but succumb to the inertia. The universe is by design, a lazy place.