It makes toast look delicious. That’s one of Notting Hill’s finest achievements – along with making dating a movie star look realistic. On several occasions a character eats a piece of toast – always rushing to do something else – and you think: “Yes, toast is the best food we have. I’m now going to make some toast.” It’s one of many reasons, big and small, that I will happily watch Notting Hill all over again as soon as its end credits roll. There are few films that keep me as transfixed, few films that make me feel like I just made good use of the last two hours and four minutes of my life.

If you’re unfamiliar with the film, a) sort your life out; b) it’s a story about Hugh Grant, travel bookshop salesman, falling in love with Julia Roberts, Hollywood movie star. Certainly the best thing Grant has ever done, it is also Richard Curtis’s finest film and I won’t hear any argument to the contrary. I should know – I’ve watched it about 12 times. (That may not sound like a lot but it’s more than a day of my life.)

What is so wonderful about the film is how effortless it all seems. The story isn’t complex; there are no gun fights or CGI raccoons; the greatest jeopardy in the film involves Grant having to catch Roberts before she goes back to America – a problem that reads as plausibly insurmountable in 1999 but today would be remedied with a few WhatsApps. But, despite the illusion of effortlessness, getting everything right in this way is deceptively tricky. Has a single romcom ever managed to marry all of the necessary elements – cast, script, timing, an intangible magic – so perfectly? (No. The answer is no.)

It is odd, in retrospect, that Curtis wrote one film in which Hugh Grant falls in love with an American woman, and then thought: “No, that isn’t enough. I must do that again.” But I will fight to the death anyone who thinks Four Weddings and a Funeral is a better film than Notting Hill. Had they arrived the other way around, I think we would remember Four Weddings less fondly. The latter is inferior in part because, let’s be honest now, it’s much harder to see what Grant sees in Andie MacDowell’s character. This makes it more difficult to care about the central love story. As soon as you meet Julia Roberts’s Anna Scott character, though she may seem aloof, you know why Grant falls for her (and to pieces over her). And “I’m just a girl, standing in front of a boy, asking him to love her” is a peerless piece of movie dialogue; “Is it raining? I hadn’t noticed” is a sad insight into someone with terrible observation skills.

Watching it again for this piece – no sacrifice is too great – I realised afresh how important Notting Hill is to me. It is one of the leanest films around, so little of it self-indulgent or unnecessary. It is crammed full of lines that are laugh-out-loud funny. Hearing Curtis talk about it on a podcast, I was reminded that of course some of its genius is that it is as much about the love of friendship as it is about the love of romance. Grant’s friends are relentlessly there for him as he thrashes around trying to work out whether or not he and Roberts can work. There are few scenes as perfect or as accurate as this one, in which Grant’s friends assure him that he has done the right thing by dumping Scott – only for Spike, the filterless friend, to call him a “daft prick”. They don’t write scenes like this any more, let alone films.

And, while the central love story is magnificent, the fact that we know it must end happily inevitably robs it of some drama. By contrast, the part that always moves me to tears is the moment in which Tim McInnerny’s character Max picks up his wife Bella (Gina McKee), who has lost the use of her legs, in order to make sure she is not left behind as the group hare towards Roberts’ climactic press conference. The “Come on, baby” he whispers while she has her arms wrapped around his neck is like heroin to me.

To anyone who hasn’t seen it, or is wondering whether to rewatch it: put Notting Hill on tonight. And make some toast to watch it with.

• Notting Hill is available on Netflix in the US and Channel 4 in the UK