The Easiest Mistake To Make In Chess

I played a game very recently (not on this site) where I was very happy to win, particularly because I was losing for much of the game.  In this game, my opponent and I both made mistakes based on the failure of checking for threats, a mistake that is all too easy to make, especially when one feels that they control the tempo.  This game I feel provides an excellent example of this.  I was Black and I have provided some annonations.  Note:  On my annonation regarding 33...Re7!, I meant to say the e1 square being targeted (not d1, as I said in the annonation).  Since I am too lazy to figure out how to fix it, I have done it like this.  My apologies.