IN 1961, everywhere else, John Kennedy was the generation-defining US President advocating hare-brained schemes such as lunar exploration, liaising with Hollywood starlets and inspiring a nation with his dreams.

In Melbourne, John Kennedy was an uncompromising coach in a gabardine overcoat, exhorting Hawthorn towards its first VFL premiership. Something that, for a downtrodden club, once seemed as likely as a stroll on the moon.

Talking with Swans' midfielder Josh Kennedy before tonight's preliminary final against Collingwood, you raise the subject of his famous family apologetically.

His grandfather John, the legendary, iron-fisted coach. His father, John Jnr., who shouldered the burden of a famous name magnificently, playing in four premierships with the Hawks.

Inevitably, it is something about which Kennedy has been reminded his entire life. Thus, when Kennedy left the Hawks for Sydney after the 2009 season, one of the game's strongest family bonds was broken - unnecessarily, some would conclude, as he became an elite midfielder with his new club.

But Kennedy is eager to make it clear there is no rancour about his move from Hawthorn. That his success has come because of his move to Sydney, not despite his move from Hawthorn. Something that could reach an interesting juncture should the Swans beat Collingwood, then meet Hawthorn in next week's grand final.

When quizzed on who his grandfather would support in that event, Kennedy says: ''You'd have to ask him'', clearly unwilling to predict footballing heresy.

Children and, in Kennedy's case, also grandchildren of famous sportsmen, paint contradictory pictures of their childhoods. Some embrace the opportunities and genetic advantages. Others shy away from the reflected glory and become determined to forge their own path.

Kennedy enjoyed being a Kennedy. Going into the rooms on game day. Getting to know the stars.

''I loved the game, so it was Christmas,'' he says.

Kennedy's childhood memories of his grandfather square with the public image of the upright, devout, disciplined character whose booming voice is a prominent part of the game's history.

''Growing up, as kids we really respected him,'' he says.

''We also didn't want to get out of line because he could come down pretty hard. With him it was family, faith, school and, only then, footy. It wasn't until I got to Hawthorn that I met a lot of people who could tell me who he was [in football].''

Kennedy never hesitated about playing football - ''I was hopeless at everything else'' - but says his father, who spent time as an assistant coach at Hawthorn, stayed in the background.

''He was only really a teacher from when I was 16 or 17,'' he says. Kennedy does not deny leaving Hawthorn was an emotional wrench. ''Absolutely it was. But I'm lucky to have the support network around me who have been involved in the game, in the business, for many years. That's made it a lot easier.''

One of five Swans educated at Xavier College, a bastion of Catholic conservatism in Melbourne's leafy eastern suburbs, Kennedy is friendly and articulate. Wearing a club singlet, he reveals a body that is both as lean as a hyena, but also broad and muscular. Perfect for spearing his way into packs, as he can do with devastating affect.

Kennedy says he was not well versed in the Swans' ''Bloods'' cult before he came to Sydney, but admired what he had seen.

''They never won by much and, when they lost, it was never by much. You knew what you were going to get. Coming up here, I felt suited to that mould.''

Jude Bolton was appointed Kennedy's mentor. It was a match made in a World War 2 Japanese fighter pilot training school. Two Kamikazes whose lust for the ball seems to increase their threshold for pain. Bolton will play his 300th game tonight.

''Amazing leader, amazing player,'' Kennedy says.

''Very lucky to play with him. He just loved the club and he wants success for everyone involved.''

Kennedy played 13 games with the Hawks, struggling to establish a place in a tough midfield packed with warriors. Regular first team selection has increased his confidence.

''That's massive for me,'' he says. ''Just being clear in what my strengths are, and what my role was each week, and being confident that if I could do that I would get a game the following week.''

Kennedy's crash and bash style takes a physical toll. The week off between the victory over Adelaide and tonight's game was welcome. In the back of his mind are the lessons absorbed at Hawthorn where he was on the fringes when they won the 2008 premiership.

''Just the way everyone bought into the game plan and had total confidence with each other,'' he says. ''That was the feeling at the time. By the end of the season I was just going along for the ride, but it was an amazing experience and something that drives me to want to achieve that as a player.''

Again, you wonder about that potential grand final match-up against Hawthorn.

''I don't know,'' he repeats, when pressed on how his famous Hawthorn family would cope. I'll let them worry about that. I'll worry about the black and white this week.''