After slighting your work, after doing a poor job, you are not quite the same man you were before.

You are not so likely to try to keep up the standard of your work, not so likely to regard your word as sacred as before.
The mental and moral effect of half doing, or carelessly doing things; its power to drag down, to demoralize, can hardly be estimated because the processes are so gradual, so subtle.

No one can respect himself who habitually botches his work, and when self-respect drops, confidence goes with it; and when confidence and self-respect have gone, excellence is impossible.
It is astonishing how completely a slovenly habit will gradually, insidiously fasten itself upon the individual and so change his whole mental attitude as to thwart absolutely his life-purpose, even when he may think he is doing his best to carry it out.
I know a man who was extremely ambitious to do something very distinctive and who had the ability to do it.

When he started on his career he was very exact and painstaking.

He demanded the best of himself--would not accept his second-best in anything.