[chongli]

Learning a language as a hobby is tough. If you don't need the language to communicate and survive in your environment then you have essentially zero real motivation to learn it.

The problem with spaced repetition systems is that it doesn't supply that extra motivation. You're still just memorizing things in a vacuum. If you truly want to learn a language you need to use it to communicate. That means making friends, travelling, reading books, and consuming other media in that language.

[Tijdreiziger]

You can also be motivated because you like to consume media in the language (relevant for English and Japanese), because you think it will be useful for a job (English) or for travel (French, Spanish, etc.), or simply because you like the language.

If you don’t have any of these reasons to motivate you, the question arises of why you’re bothering in the first place.

[chongli]

I started learning Mandarin on Duolingo while dating a Chinese woman. After we broke up I continued with it just because I found it fun.

Now I have several Chinese friends and I'm learning Chinese cooking. I'm motivated to continue learning about Chinese food and Chinese culture, and the important role food plays within it.