This expression is used when a person does or tells you something you already know and thinks it is absolutely amazing.
Person 1: She got a hollywood wax for the first time.
Person 2: let me guess its the most exciting thing since sliced bread for her.
Person 2: let me guess its the most exciting thing since sliced bread for her.
by sealion3 December 26, 2012
Get the most exciting thing since sliced breadmug.