Robert Redford for the win!
My password is password.

I adore Olivier, but he was terrible in this film.
If you can’t say something nice, say something clever but devastating.

This was the first movie of Diane Lane's illustrious career. Laurence Olivier's role was greatly expanded from that character in the book.

Diane Lane was adorable. Otherwise, not very memorable. The young boy annoyed me. Oliver was wasted.
If you can’t say something nice, say something clever but devastating.

I'm a romantic so it is a favorite.
Odd that part of the reason you don't like is because you dislike teen actors. They did a really good job and were very authentic.
The dialog was amazing on several levels.

Is it the same flick which the OP of this thread describes as 'perfect'?
Because I would hardly shower such gushing laurels on it. It was –as you say –'engaging' but in a rather mild degree.
I didn't think anyone else would even remember it around here, save myself.
I watched it only for the sake of seeing Olivier. Otherwise, mere location-photography in some European capitals all too often winds up just a 'travelogue' movie.
Like in this case, it wasn't Antonioni behind the camera; nothing particularly magical composition-wise.
The pedestrian story stayed centered on the two teeny-boppers and the tame
"how old does one have to be to fall in love?"
storyline.
Lord do I loathe children / teens in cinema.
Paul P. Powell, Pool Player

ALR was set in Paris, Verona, and Venice. A beautiful, engaging film.

'A Little Romance'
starring Sally Kellerman, Arthur Hill, two bratty twerp kiddie actors, and Larry Olivier?
Nothing you describe rings a bell. The flick I saw was set in Paris.
Paul P. Powell, Pool Player