My daughter said "I hate myself"?

My daughter (28 months old) was in the car the other day, and said "I hate myself". I said "What?!" and she said "When I'm lonely, I hate myself". My husband and I said "No! You love yourself! And mommy and daddy love you..." etc. Anyway, what do you think would make a two and a half year old say such a thing? She does know what the word "hate" means (unfortunately), and often says things like "I hate broccoli" (and, yes, I tell her that isn't a nice word and give her alternate suggestions of words to use). She also knows what the word lonely means (sometimes she says her dolls are lonely if they are upstairs while we are downstairs). Do you think she is just repeating something she heard somewhere, or do you think I should be concerned that she would say something like that?