The only justification for our concepts and systems of concepts is that they serve to represent the complex of our experiences; beyond this they have not legitimacy.
Everyone nowadays lives through too much and thinks through too little: they have a ravenous appetite and colic at the same time so that they keep getting thinner and thinner no matter how much they eat.--Whoever says nowadays, "I have not experienced anything"--is a simpleton.
When one has finished building one's house, one suddenly realizes that in the process one has learned something that one really needed to know in the worst way - before one began.