The first line is the most important.
That is a very good, and important, observation. Bob Dylan puts it a bit differently:
I’ll stand on the ocean until I start sinkin’
But I’ll know my song well before I start singin’
Our individual and collective assignment, today, is not to revisit that "first line" decision we either made, or didn't make, in the past; it is always to decide where we should go from here!
No matter what line we drew yesterday (and our past choice, of course, is affecting our current situation), we have an opportunity, today, to draw that "first line" again.