This movie is very beautiful.
The scenery and cinematography are great and the type of filter or film they used gives nostalgic vibes.
I think acting is very good, especially by the ML, he was great and I really liked the dynamics between the characters and the banter.
The introspective journey paired with the scenes, the train rides and the beautiful landscapes give you all the feels and I found myself grinning for a big part of the movie because of the little endearing moments here and there like the one with that young traveler in the snow.

Everything was great for me until towards the end when they dropped the EXTREMELY over used troupe that it's also actually very predictable from the start.
That was such a shame and it really spoiled it for me.
There are just so many things that could have been done with the plot, the most plain one being just simply that time passed, that there was a long distance between them. I really wanted a trip for the sake of introspection, self-discovery and peace but we sadly got this once again, and at least I guess he knew and it was not a bomb like they do in other movies/series. I really wish this plot device was left in the 00s where it belongs. I'm so over it at this point.

The plot in general is not new even leaving out that cliché at the end and the execution is not exactly great either. While the flashbacks are carried out in an ok manner the last part showing her side in that way for cliché/shock value was both confusing at times, repetitive and just wallowing in the drama for the sake of it.
Moreover, they knew each other for like a month I think it was, so it's too extreme that he's still hang up on that 18 years later to the level of affecting his career in that way. Also equally unrealistic in my opinion that he only had one 3 months relationship in all that time, what level of workaholic are we talking about?

It's really as described by the tag, bittersweet, although for me because of the lost potential and not what happens in the plot.