The 'Parallel Lines' meme is a clever play on geometry that has evolved into a versatile metaphor for missed opportunities and destined separation. At its core, it references the mathematical definition of parallel lines—lines that stay the same distance apart and never intersect—paired with the melancholic punchline that they share so much in common but will never meet. Over time, the internet has adapted this template to describe unrequited crushes, rival companies with similar goals, or even niche technical concepts that mirror each other but never integrate. It remains a staple in 'nerd humor' circles for its blend of academic logic and emotional resonance.