The good thing about being a teacher is you can always work part-time or pick up private tutoring. While being in a room full of brats isn't my idea of how to spend the golden years of a career, a few select kids could be enjoyable.

Having summers off and winter holidays, working from 9-3ish is practically retirement anyways compared to jobs in the private sector (no offense). Just be lazy, stop doing extra-curricular you don't enjoy, use student teachers for everything possible, mentally check out and collect a paycheck. There's unions to protect you. When it comes to writing report cards, who cares, bare minimum.

Why limit oneself to a mediocre retirement with a 10k buffer when you can have an extra 10k per year?