1
general::
Something is always changing or happening, as in First Lauren spits up, then she coughs, then she sneezes? never a dull moment with this baby! This expression was first recorded in 1889.
American Heritage Idioms
2
general::
Phrase(s): never a dull moment
[it’s] always exciting around here. (Describes an exciting or hectic situation.) • Every time I visit Jean, she has dozens of things planned for us to do: parties and theaters to attend, restaurants to try, scenic places to see. Never a dull moment. • Alan: How was work today? Jane: First of all, my boss called me in to yell at me. Then I had to fire one of my subordinates. And then my desk chair broke when I sat down on it. Never a dull moment.
McGrawhill's American Idioms And Phrasal Verbs