'Selective Memory' - is it a sin?

... some time ago - i understood Predicate Logic Basics, then quickly forgot ... perhaps in future it will be better.

... my memory is 'selective', i only remember what's important at given moment.

... it's psychological weakness ... some think that i abuse this argument, but it's medical issue.

... i was accused of 'selective memory' at youth as well - i think it was unfair.


... in psychiatric hospital i heard that 'schizophrenia is memory-related illness', more or less.

... not sure if it was psychiatrist, psychologist or other medical personnel who told me that.