Cowardice... is almost always simply a lack of ability to suspend functioning of the imagination. Ernest Hemingway
As an instructor, you must be able to distinguish between poor performance caused by lack of ability or aptitude on the part of the student and poor performance caused by lack of effort. You should treat the first with patience and the latter with firmness. You must never apply sarcasm and ridicule. Bruce Lee
The easiest thing to do, whenever you fail, is to put yourself down by blaming your lack of ability for your misfortunes. Washington Irving
Fame is hollow. It amplifies what is there. If there is any self-doubt, or hatred, or lack of ability to connect with people, fame will magnify it. Alanis Morissette
Most people who fail in their dream fail not from lack of ability but from lack of commitment. Zig Ziglar
Apart from the fact that I've got a strange job, I do lead a fairly normal life. I do my own shopping. I don't feel constrained by who I am because of what I do; I often feel disappointed by my lack of ability. I get frustrated at myself, but I think everyone does. Robert Smith (musician)