Eugene Ionesco created the play out of his being trained to learn English by writing sentences in English over and over. It became so repetitive that the words lost their meanings to him. But, this sparked the idea for his play, that what we say seems to lose all of its meaning when we don't know what we are saying and when we aren't truly communicating with anyone. The characters in this play seem to be lost in their minds as their responses to one another make no logical sense in respect to what they have just heard, yet the conversation goes on...and on.
Ionesco is alluding to how we have lost our ability to truly communicate with each other as our minds are in one place while our words continue to come out, and where does that lead us? From the ending of Ionesco's play we see that it leads us into a regurgitated cycle where we all become interchangeable. This is clear when The Martins take the place of The Smiths and begin reciting their lines before the curtain is drawn.
It is comedic because it is tragic, it makes one laugh because there is a recognition of the truth within the absurdity they are witnessing before them. Whether they recognize the truth within themselves or simply put it off to belonging to 'someone I know' relates to a deeper issue of identity. One that Ionesco, in a alternate ending--which never was played, sought to deal with by having the audience antagonized by the author or manager. In essence, to wake them up to being part of this sick-cycle.