The "All the world's a stage" speech that Jacques makes in Act II scene 7 in the play is famous for the way that it presents the world as a stage and everyone in the world as players on it. The division of the human life into seven distinct stages has been seen as a way of charting the course of human life. However, we must be aware of the way in which the speech of Jacques interacts with the themes of the play as a whole and how others interact with the rather grim and bleak view of life that Jaques himself presents.
On the one hand, there is a sense in which we can view the various stages of man as being rather humorous, in particular the way in which the lover is described as sighing "like a furnace" and how he makes poetry dedicated to the eyebrow of his lover. However, on the other hand, there is definitely a pessimistic and very bleak outlook on life that is communicated with the rather unyielding description of old age that awaits us all:
Last scene of all,
That ends this strange eventful history,
Is second childishness and mere oblivion,
Sans teeth, sans eyes, sans taste, sans everything.
The way in which Orlando carries Adam to the banqueting table of the duke and the depiction of Adam being very much alive and retaining his faculties seems to deliberately challenge such a depressing view of the world. We need to remember that this speech reflects the pessimism and sullen nature of Jaques himself, and whilst it can be useful to view life as being made up of different stages, we can perhaps recognise that those stages can be characterised in more productive ways.