1) Decisions, both good and bad, can have significant impacts and costs in our lives that may not always be gratifying.
2) The author discusses their own decision in 9th grade to improve grades, which required sacrificing free time and stress, and Harry Potter's decision to fight Voldemort that led to the death of his godfather.
3) Barack Obama's decision to become President has brought harsh criticism and threats against his family despite being a good decision, demonstrating how impactful and costly even positive decisions can be.