Just as Thompson entered his graduate program, his partner got a great job and they moved across the country, so Thompson was unable to finish his degree right away. Then, after he finally did, he landed his dream job, but shortly after that, he found out that he had cancer, so he had to decline the job offer. Each time Thompson encounters setbacks, he bounces back from them and keeps moving forward. This characteristic is known as $\_\_\_\_\_\_.$

realism

resilience

optimism

overconfidence