Where the name First and Second Act comes from

Matt's family's initials seem to spell words.  For example Matt A. Thompson spells MAT.  His brother Brad A. Thompson spells BAT etc.  So when Matt found out my initials A.C., he said that it was perfect because I would fit into the family as I would be ACT.  When Alyssa was born and we neamed her Alyssa Courtney Thompson, he loved that he would now have a first and second ACT.