Who's to say

Who's to say, what is, is best? 
Who's to say, we'll win or fail? 
Who's to say, we've come too far, 
To blaze a brand-new trail? 
Who's to say that we'll survive, 
or fall off by the wayside, 
Who can say, we've done our best, 
or whether our egos will coincide? 
Who's to say, that's right, 
that's wrong, 
or whether we'll have it all? 
Who's to say, we'll climb the heights, 
Who's to say, we'll scale that wall?