He came from a broken home, which is to say a cocaine-fuelled madman had crashed a JCB into his house, and his mother would come in with him to the surgery until he was in his early twenties.
Like all Irish mothers, she managed to be both soothing and reassuring yet frightening and intimidating all at the same time, and if that was her effect on me, what was it like for Joe? He was so complicated he should have come with a manual.
A chubby chap, like Oliver Hardy (without the sense of humour), he was a firm subscriber to Dylan Thomas's philosophy: 'Do not go gentle into that good night/Rage, rage against the dying of the light,' but decided to so subscribe at an inappropriately early age.
Every symptom was a cause of immediate and bitter anguish but also a harbinger of disaster further down the line. Optimism, he believed, was the result of intellectual error; timor mortis conturbat me might have been his motto.
His one release was his interest in Gaelic football. In Crossmaglen, we are fortunate to have a mighty team, with innumerable county titles and a few All-Ireland championships. But even this interest was coloured by his implacable pessimism, allowing him to be always armoured against defeat and alert for disappointment.
'That'll be no good against the Kerry and Cork teams,' he'd opine, after we hoovered up yet another Ulster title. Even if we were 20 points ahead, when the opposition broke briefly upfield he'd say, 'I told you this would happen,' in a doom-laden tone.
And if they managed a consolation score, 'Ah, we're bate now,' shaking his head sadly, like a fat Irish Cassandra prophesying ruin before the gates of Troy. Winning the All-Ireland entailed no joy, no living in the moment, just visions of a bleak future: 'That's the last one.'
Nonetheless, because I am sometimes a good doctor, I somehow persuaded Joe to take up regular exercise and less than a year later, he completed his first marathon, in under four hours.
'That was brilliant, Joe,' I said, hoping that a surge of endorphins would have modified his brain chemistry.
'My feet are killing me,' he said.