I try very hard to avoid committing to anything so I can avoid letting people down, because my health is unpredictable and if I can't do something after saying I would I feel absolutely terrible about it, even if I'm told it's nothing to worry about. It's not like it happens very often if I agree to do something, but there is always the pressure and the worry that it will, so I generally just don't make promises. I've always thought that promises should be kept.