If you attempt certain things at the right time, they are easy to accomplish - in fact, they almost get done by themselves. If you undertake them before the time is right, not only will they fail, but they will often become impossible to accomplish even when the time would have been right.
Francesco GuicciardiniLet no one trust so entirely to natural prudence as to persuade himself that it will suffice to guide him without help from experience.
Francesco Guicciardini