I’ve never understood how aphorism, “hindsight is 20/20” came to mean that one’s understanding of past events is clearer than one’s contemporaneous understanding of the same events. 20/20 means normal vision (being able to clearly see at 20 feet what one should be able to see clearly at 20 feet), so this saying literally means that upon reflection, things in the past are as clear as they should be to one of normal vision. Huh? There’s a disconnect here. That’s why I rewrote the popular staying as:
Hindsight isn't 20/20 — it's at least 20/15, and sometimes 20/10.