When I first read these words several years ago, quite a while before I knew anything about God, I was going through a really rotten time in my life. I was unemployed, living alone in squalor, and hopelessly addicted to homemade morphine tea, which I creatively derived from poppy pods and seeds. I was collecting unemployment, which wasn't enough to pay my rent and bills, and I owed hundreds of dollars to family members who had been helping to support me. I had also sold everything of any value that I owned, including my personal library of almost a thousand books which I had been maintaining and adding to for over twenty years, mostly to support my drug habit. I was not a happy person.
At the time those words... 'the sadness will last forever'... struck me as being the most honest words ever spoken, at least for me. I truly believed that my debilitating sadness, which had led me to seek an escape through drugs to begin with, was never ending. I had no real hope, and at one point I even composed a suicide note. I think what caused me to skip over that option at the time was that I couldn't send it to anyone immediately because I had no internet connection and I was out of printer paper, and I was far too apathetic to actually make the effort to send it.
At that time 'forever', to me, merely meant the rest of my life, and I'd been of half a mind to shorten that concept drastically to something more manageable. Since then, however, I've gained a modicum of hope in my life, but ironically, I also believe that the sadness can last forever when separated from God, so I view them far more literally now than I ever did then.
These were the last words of Vincent Van Gogh. It is said that his favorite color was yellow, which stood for the light he dreamed of being in the hearts of people.