A Decade-Old Euler Solution Shows How Much Cleverness AI Has Quietly Replaced

Revisiting a 10-year-old Project Euler repository, the author finds a solution to Problem 15 (counting lattice paths through an n×n grid) stored not as code but as a plain text file. The student-era answer skips programming entirely: recognizing that path counts follow the central binomial coefficient (2n choose n), it computes 40 choose 20 = 137,846,528,820 by hand reasoning rather than brute force, memoization, or dynamic programming.

The contrast with the author’s present-day instincts drives the piece. Faced with the same problem at work today, they imagine reaching for Python and looping their way toward a solution — or, more honestly, just handing it off to an AI and moving on. The younger self’s purely mathematical insight reads, by comparison, like recovered knowledge from a more rigorous age.

The post is a short, self-deprecating reflection rather than a technical tutorial, but it lands on a real anxiety in the developer community: as AI absorbs problem-solving, the discrete-math fluency that once let engineers sidestep code altogether risks atrophying into a skill we no longer practice.