Why this matters
Every else branch creates a parallel path through your code. The reader must track both the "normal" and "alternative" flows simultaneously. Guard clauses and early returns collapse these parallel paths: handle the edge case first, then write the happy path straight down the page — no branching required.
Code Challenge
Study the messy code, try to refactor it, then reveal the clean version.
Key takeaway
Return or throw early for every special case, then write the normal path without any branches. Your readers will thank you — they only have to follow one path at a time.