In an F1 career that’s spanned over 300 races – a milestone only three drivers before him have reached – 37-year-old Alonso has done it all: dethroned the great Michael Schumacher, won multiple races for McLaren and Ferrari, and established himself as one of the undoubted greats of Grand Prix racing.
That he hasn’t been able to add a third world title to his CV may stick in his craw, but only the churlish would forget he was a runner-up on three occasions, often going closer than many thought his machinery would allow.
But while he's stepping away from F1 next season - and note, the word 'retirement' was not mentioned anywhere in his or McLaren's statement - there's no suggestion he's hanging up his helmet. Indeed, Alonso remains as hungry for success as ever, which explains why, with his race-winning ambitions currently dented by uncompetitive machinery, he has in recent years set his sights elsewhere.
Having completed the second leg of the fabled Triple Crown earlier this year - when he added victory in the Le Mans 24 hours to his two Monaco Grand Prix wins - the smart money is now on the Spaniard returning to IndyCar for another bid at Indy 500 glory. Winning that race - and emulating Graham Hill’s famous and up-to-now out of reach record - will be no easy feat as he learned in 2017 - but attempting it as part of a full blown campaign can surely only increase his odds.
And if he were to achieve his goal - and McLaren were to improve significantly - Alonso could well find himself back on the F1 grid in 2020 aged 39. And let's not forget, Nigel Mansell - one of only a handful of drivers to win both Formula 1 and IndyCar titles - was a world champion at the same age...
What will McLaren do?
But just as interesting a question as what Fernando does next is what his current team, McLaren, will do without their talisman. Do they retain Stoffel Vandoorne and add one other, or will they wipe the slate clean and look at building an entirely new driver line-up?
In either scenario, who do they bring in? Do they promote young talent Lando Norris from F2? Could they provide a home for Carlos Sainz, who was recently jettisoned from Renault to make way for Daniel Ricciardo? Or could former pilot Kimi Raikkonen make a shock return if he's deemed surplus to requirements at Ferrari? One thing is for sure: Alonso’s move has reignited an already fascinating driver market and at this point it feels like almost anything is possible...
For now though, Alonso and McLaren have nine more races together and both parties will be hoping to go out on a high.
We'll miss him when he's gone.