"when I do good I feel bad when I do bad I feel bad"
    -Abraham Lincoln

what this quote means  is that when you do something good or right you feel proud of your self. Because you had accomplish something right or good.But in the other hand when you do wrong or you do bad you feel sad or mad or disappointed on you self because you didn't accomplish your assignment or your achievement.

An example when I feel good is when I study on a test.I feel good because I know done good and eventually  I will past the test .But when i feel bad is when i don't study for the test. The reason I will feel dad is because i didn't study at all and eventually i wouldn't pass the test and will fail the test