Invincible Phases

Hi guys.  Me again!  My rounds yesterday and today have been those where you just cannot do anything wrong.  And you feel so confident on the course.  The round before that wasn't particularly good (net one over par) but something seems to have just clicked.  For those of you who don't know me, I have returned to golf recently after a two year break from the game (due to personal circumstances but I won't bore you with the details.  It is the ultimate buzz kill).  Anyway, I used to be a 14 handicap and I am trying to get back down to that.  I have gradually being chopping away at my handicap but right now, I feel invincible. 

When I was playing the game before I had to quit, I remember having horific phases where nothing would go right, and then there were the phases where almost everything goes right.  On the golf course I mean!

I have just realised I digressed for a bit but what I am trying to say is, does anyone know why we have these phases?  Even if we aren't changing our techniques.  I am positive I am not the only one who experiences this.  Almost everyone I have played with has these "phases".  But it would be very intersting to see if we can find a reason for this.

Thank you in advance for any constructive input