I had an American private student in the 80s who was in London because her husband got transferred here for a stint of work. She was in her 20s, I think (or early 30s at the most -- I'm very bad with age).
She was planning to apply to Columbia University for a postgrad in Business Studies. One of the criteria was knowing a second language (just like for the London Business School MBA programme, where I taught Mandarin to the students for a couple of years). As this was the 80s and China was opening up to the outside world after the Cultural Revolution (1966–76), she decided to go for Chinese for that second language.
The Chinese language is mostly SVO (Subject Verb Object) in structure, e.g., 我喝茶 / wǒ hē chá / I drink tea. This matches English, so lots of English speakers do not have a problem with it.
One problematic structure for lots of Mandarin learners is the 把 bǎ construction, with the (for Mandarin) unusual word order of S 把-O V (e.g., 我把茶喝了 / wǒ bǎ-chá hē le / I took the tea and drank it).
This American student struggled with this, and said, "What a stupid language!"
I was stunned by this attitude: calling a language "stupid" just because she couldn't cope with a construction that does not conveniently match English that she's comfortable with.
I say "comfortable with" for a reason, because English is not the most consistent of languages, yet English speakers don't object to this, because they grow up speaking it -- what I call the osmosis effect: it all seeps in and stays under the skin, without the speaker noticing it.
As a lot of my students will know, I'm constantly sympathising, and empathising, with them, calling the Chinese language a monster, which makes them laugh (and feel better about their own struggles), so my feeling shocked about the attitude of this student was not in defence of the language at all, and certainly not because I'm from that cultural background.
My concern is purely from a pedagogical perspective, which I always explain to the student: "Taking this attitude is counter-productive. Since you've launched into it (learning the language), you have to block out all negative thoughts, or it'll hamper your coming to grips with an already challenging task which you can't do anything about but to devise coping strategies for. Or give up."
When students say that they're too old or too stupid to learn such a hard language, my immediate response is, "That's the first thing you should do: try and stop taking that attitude. If you say it often enough, you'll start to believe it -- this way, the battle is lost before you've even started."
I give the same advice even when I hear people talking about being too old or too stupid to learn anything else.
Of course, I'm not saying that just thinking that you can become fluent in Chinese or German or French will immediately remove all the obstacles. We have to be realistic and recognise (/acknowledge) that some of us are not cut out for certain things in life, e.g., being an Olympic athlete, or a UN interpreter. Some people are born with a talent for music, some for carpentry, so one has to be aware of one's limitations, it's true.
This American girl was aiming to do an MBA with Mandarin as her second language. With such an attitude about the language (calling it "stupid"), she wouldn't get very far, I feel... (With learning the language, I mean, not in life, although her attitude would probably also throw a lot of self-created obstacles onto her path through life.)
(London, 1987?)