"مَن أحسنَ الظنَّ بنفسه ضَلّ."

.

.

.

لَا أُقْسِمُ بِيَوْمِ الْقِيَامَةِ • وَلَا أُقْسِمُ بِالنَّفْسِ اللَّوَّامَةِ

[سورة القيامة]

.

That adult learners cannot achieve a native-like accent in their L2 [second language] has also been challenged.
Some investigations reveal that a small proportion of adult learners can attain native-like accents, and fall within the range of native speakers; moreover, they cannot be reliably distinguished as second-language speakers by native speakers. Likewise, a small proportion of adult L2 learners can apparently attain native speaker-like competence. These observations contradict the frequently heard claim that it is impossible for an adult learner to gain full control of a second language. But they do not contradict the generalization that the older one is when exposed to the L2, the more difficult it is to learn the language, and the less successful the learner is likely to be.

— Linguistics, by William B. McGregor

The distinctive pattern of cracks on the surface of an old painting.

When you fall in love, at first you take your lover for a work of art; her visage a painting, her voice a melody, her quirks a curiosity. Then you meditate longer and gaze deeper into the art, and the brushstrokes, cracks, and faulty details start to show themselves and catch your attention, and maybe distress. But if you're still in love, even the cracks and paint flakes will look like craquelure and Persian mistakes to you—signatures of authenticity and beauty.

You may have noticed this in yourself: you fall in love with an olive-skinned brunette, and suddenly Venus herself has brown hair and a tanned complexion; you're enamored with a blue-eyed freckled girl, and freckles become the epitome of beauty.

أسَرتِ وحَرَّرتِ الفتى بجَمالِك
فليسَ بمَملوكٍ وليسَ بمالِك

تَحَرَّرَ من ظُلمِ الحِسانِ وإنْ غَدا
متى يَرَ حُسنًا قاسَهُ بِمِثالِك

— تميم

If we judge of love by the majority of its results it rather resembles hatred than friendship.

إنْ حَكَمنا على الحبِّ بنتائجه، فإنّه بالكُرهِ أشبَهَ مِنهُ بالصداقة.

There is real love just as there are real ghosts; every person speaks of it, few persons have seen it.

الحبُّ الحقيقي مِثلُ الأشباحِ الحقيقية؛ كلُّ الناسِ يتكلَّمون بها، قليلونَ جدًا هُم مَن رَأَوها رأيَ العَين.

It is more disgraceful to distrust than to be deceived by our friends.

مِنَ المُعيبِ أكثَر ألّا نَثِق بأصدقائِنا مِن أنْ نُخدَعَ مِن قِبَلِهم.

Obsessive thoughts (such as in anxiety disorders) can cause a behavior that looks quite similar to that of ADHD, even though the cognitive mechanisms are different. It's like how fever can be caused by both lymphoma and tonsillitis.

Imagine giving stimulants to someone with generalized anxiety disorder