If one has thought, even if only once and just briefly, that there are no better days to come, that the future will only be more of the same, that one has felt it all, then one has reached true adulthood. Just as childhood ends with the realization that one must eventually die, adolescence ends with the realization that there is nothing new under the sun, that this is all there is in life and that after this brief, clichéd passion play there is only eternal nothingness.
And while no thought could be greater cause for despair, there is also something to be grateful for in it: afterwards no pains will ever again sting as much and the little sting they give comes more from anger with oneself than from anything else — one is ashamed of having been stupid enough to think anything could be different.