Should(n’t)

I don’t always know
   where the line is –
       when I should shut up
               so I don’t
                   cause any additional trouble or
                   hurt someone unnecessarily
                           and
        when I should speak up
                so I don’t
                   suddenly blow up later.

There are many times
   I am thankful
      that I didn’t say
      what I wanted to say
         at the time
      I wanted to say it.
                But.
There are also many times
   I never meant
      to get so mad
         about something
            that shouldn’t
               be such a big deal,
            and wouldn’t
               have been,
                      if
                  I had just spoken up
                     earlier.

How do I know the difference
         between
         the
         two
     in the moment?
Before it’s
   too late
        to say something
          or
   too late
        to take it back?