Meaning:
To have experienced the topic under discussion, to the point of boredom or complacency.
Origin:
This phrase began life in the early 1970s, in the short form 'been there', which had the same meaning as 'been there, done that'.
Source: The Phrase Finder
We all have heard the phrase 'been there, done that' quite often on American sitcom shows. But obviously, this phrase sounds rather informal and necessitates a careful application. So, it may not be appropriate to use it in certain situations.
Is there an alternative phrase that sounds less laid-back but hits the nail at the same time?