The occasion is being marked by An Post issuing a commemorative stamp in his honour.
While this recognition is deserved, my own hope is that the man will be commemorated for the small number of superb stories that he told – through books and plays – and not for the numerous stories that pub bores love to tell about him.
Invariably these are comic tales involving drink. But 50 years on, it's time to recognise that there is nothing comic about illness, be it diabetes or alcoholism – a combination of which caused Behan's early death at 41.
Genius is an over-used word, but in so much as Behan possessed an element of genius it was in spite of the fact – and not because of it – that during his final years he publicly acted out the role of being "a broth of a boy".
There's a thin line between being remembered as a "character" and being remembered for a monumental waste of talent.
Behan's talent wasn't wasted in that he produced a superb memoir, Borstal Boy (containing such home truths about the folly of mindless political violence that the Irish Censorship Board banned it, ironically, on Armistice Day in 1958).
Several of his plays are still widely performed.
There is no guarantee that he would have written new works to equal these if he had lived into old age. Inspiration can be a fickle mistress, and by the age of 41 – reduced to drunkenly dictating into a dictaphone – he may have had nothing left to say.
But we will never know what later work Behan might have produced, because he died too young, a victim not only of his illnesses but of Irish society's tolerance of the myth of drunken geniuses.
At the time Borstal Boy was published, Ireland seriously needed to hear the honest self-truth in Behan's journey from unthinking hatred (dispatched as a child bomber to Liverpool by his IRA masters at 16) to learning to think for himself during three years in a Suffolk borstal.
But the Irish authorities were determined that no fresh ideas would disturb the intellectual torpor imposed on the State.
Such was the atmosphere in which Behan worked.
This stifling intellectual climate meant many writers followed Joyce into exile, but others stayed and fought censorship.
Few did so with more courage than Alan Simpson and Carolyn Swift in the tiny experimental Pike Theatre. In 1954 they put on Behan's first play, The Quare Fellow, which was rejected by the Abbey and the Gate.
This helped create the momentum for Behan's most famous play, The Hostage, which brought international acclaim in 1958.
The Hostage and Borstal Boy should have proved the launchpad for a wondrous career because, 50 years on, they remain classic works.
The tragedy was that by 1958 Behan was becoming as well-known for his drinking as his writing; for being the ultimate dangerous live television guest; for unprintable soundbites and missed deadlines; for riotous scenes in hotels and airports; for the fact that – long before the age of celebrity – he became an international celebrity.
He became the George Best of writing: a man suddenly swept up inside a new world of temptations, with no predecessor to learn lessons from about how to handle fame. The world was at his feet and there is nothing more dangerous.
The discipline of being a writer locked away in a room might perhaps have saved him. But by 1960 he discovered the tape recorder. His final books were rambling dictated mishmashes – Brendan Behan's Island and Brendan Behan's New York.
Fame brought wealth and spongers and a descent into a nether world in which he was the writer who no longer wrote, the burnt-out mumbling raconteur.
This is the Behan passed down in Dublin folklore over the past 50 years, a drunken genius, a man who acquired more friends the longer he was dead.
It's a dangerous myth and one that as a young working-class writer I briefly felt I was expected to try to live up to. Thankfully, I copped-on and realised that writing is not done in pubs but soberly in quiet rooms.
Thankfully, many other writers who suffered problems with similar addictions to Behan learnt enough from his self-destruction to overcome the illness that overcame him.
I am delighted to see a stamp issued in his honour, but let us remember it is not being issued for the attention-seeker deliberately cursing on television.
Look behind the monotonous drunken stories and you will find the wit and self-awareness of his great memoir and see a different legacy to commemorate.
Behan as a young self-taught craftsman, expressing home truths in a time when truth was always banned in Ireland.
He battled illness and battled to stay true to himself in an impossible situation, one where all your dreams of fame suddenly come true.
If you want to know the man on the stamp, don't bother listening to the pub tales and myths.
Go back and enjoy the words he wrote, long before he ever expected that a tide of fame would sweep him up and send him crashing to his death, 50 years ago this March 20.