How I play It's complicated on my Acoustic guitar. Hope you will enjoy and please 
leave a rating :)

Standard tuning. 
Tip. Its nice to play the chords open like power chords but you still play the empty strings.

Powerchords      Normal chords
C#m (X46600) -- (X46654) C#m 
A   (X02200) -- (X02220) A 
E   (022100) -- (022100) E
B   (X24400) -- (X24442) B


Verse:
         C#m              A   
Here we go again, another night of being bummed
       E
I keep to myself, avoid the sun
          B
And cancel plans with everyone

   C#m                A
I know cause its just how it always ends
   E
Our bond will break cause you can't relate
B                         A (hold this chord)
To anyone, to anything at all

Bridge:
                 C#m           B         A
You brought your worst and I'm right here
                 B  (guitar silent for this part)
Now I've seen it all, and it's never been so clear


Chorus:
E                            B
You're not the person that I knew back then
A
It's all too late to set things straight cause 
C#m            B
everything has been
E                            B
You're not the person that I knew back then
A
Lets try and act like this didn't happen
C#m                          B
Follow your friends like you ever had them


Verse:
              C#m
You still know me
              A
Still not cut out for this sort of thing
      E
Never want to be, caught in between
       B
I need constant reminders of everything
          C#m                         A
So what! It's who I am, but I think I played it off so well
E
I just hold it in, no matter how I've been,
B
so nobody, nobody can tell

Bridge:
                 C#m           B         A
You brought your worst and I'm right here
                 B  
Now I've seen it all, and it's never been so clear


Chorus:
E                            B
You're not the person that I knew back then
A
It's all too late to set things straight cause 
C#m            B
everything has been
E                            B
You're not the person that I knew back then
A
Lets try and act like this didn't happen
C#m                          B
Follow your friends like you ever had them