What does it mean by “I’m happier than I’ve been in a long time”? Does it mean I’m “happier” than ever(like the happiest in my life) or “as happy as” before?
That expression means that they are more happy than they have been for a certain period of time, indicating that at one point in time they were as happy or more happy than they were now. Consider this example:
Ten years ago I lost my job and the past few years were rough. However, I got a new job, one I really like. I'm happier than I've been in a long time.