I first saw Up when I was 40,000 feet high in the sky. Unlike the lead character of the animation, however, who travels the world by helium-balloon-powered house, I was on a plane en route to my cousin’s wedding. Little did I realise that within 10 minutes of putting my headphones on and pressing play, I would be reaching for my travel tissues and stifling sobs as passengers either side of me stared awkwardly into their complimentary peanuts and pretended not to notice.

The somewhat unexpected hero of this 2009 Pixar classic is Carl Fredricksen, a balloon salesman in his late 70s who lives alone after the death of his wife Ellie. The animation starts further back in time, however, with Ellie and Carl meeting as wide-eyed, button-nosed children dreaming of exploration as they soar across the wilderness of their imaginary worlds in matching aviator goggles.

Facebook Twitter Pinterest Up was the first animated film ever to open the Cannes film festival in 2009. Photograph: AFP/Getty Images

In quick succession, the two grow up, fall in love, get married and build a home together. But time presses urgently on, and soon we see Ellie on her deathbed handing Carl her well-loved book of adventures and telling him it’s time for one of his own. Some films may try to tease out a tear at some point along the way and never quite achieve it; Up has you with this opening sequence and doesn’t let you go.

Yet, magically, despite heart-wrenchingly understated scenes like Ellie’s death, Up is always one step ahead, making you laugh out loud just when you least expect it. Carl’s totally non-action-packed trip from the top to the bottom of his house via a stairlift is the perfect example – but perhaps you have to see that one to appreciate it.

Up is a film about getting old, about regret and about realising that life is messy and out of control, as much as you might try to make it otherwise. But it’s also a film about love, compassion and making sure that every day counts. Which is exactly what Carl does. When the local authorities try to send him off to a retirement home, Carl realises he has one chance left to do his best by his late wife, so he ties hundreds of helium-filled balloons to their home and floats the house out of the bustling city and across the tops of the clouds towards the place he and Ellie had always dreamed of visiting.

It’s only when Carl is thousands of feet up that he gets a knock at the front door and realises he’s brought an unexpected guest with him – a lovably useless local kid called Russell, who found himself on Carl’s front porch when the house took off. Proud he’ll be able to help navigate the journey using his GPS tracker, Russell throws his arms open enthusiastically, only to mistakenly lob the location gadget out of the window on to the clouds below.

“Oops”, says Russell, as he and Carl watch the flying object hurtle away from them. And so the pair’s adventure really begins.