Grad school can be tough and overwhelming and so someone feeling like they are on a cruise and handling things perfectly is unrealistic and speaker dropping out of grad school shows that they were not really handling things perfectly after all.
Consider the statement "I was really stressed out and grad school and had no choice but to drop out to keep my sanity. ". Based on this "I was handling things perfectly and grad school was making me feel like I was on a cruise so I dropped out to keep my sanity." a true statement? Yes, no, or I don't know?