The current recovery phase, which started in December 2012, seems to have lasted for 64 consecutive months by March 2018. Sources: Cabinet Office, etc.
Second, the post-crisis low interest rate environment laid the ground for central bank communication to play a key role, and also for it to become much more forward-looking. Economic agents act in a forward-looking way, but they must manage a vast amount of information surrounded by a lot of uncertainty. As such, it is important to guide them to formulate appropriate expectations.