The BFSLPE (Big-Fish-Little-Pond Effect), first mentioned by Marsh and Parker in 1984, describes how people of equal compatibility have differen self-concepts, depending on the peers in their direct environment.
E.g. Students in low-socioeconomic (SES)/low-ability schools have a higher conception of their own abilities, than same ranking students in high SES/high-ability schools.
One common example mentioned is that of the highest achieving student in high school, who then becomes an average student in University. Most likely, because the highest achiving students all go to an equal high-ability university.
Example: Not leaving a bad concert early, because you already paid money for it.