Although the optimist may be a little giddy when foreseeing the future, telling himself that it will all work out in the end when that isn't always the case, his attitude is more fruitful since, in the hope of undertaking a hundred projects, followed up by diligent action, the optimist will end up completing fifty. Conversely, in limiting himself to undertake a mere ten, the pessimist might complete five at best and often fewer, since he'll devote little energy to a task he feels to be doomed from the start.