"Page by page I slowly and lucidly reread everything I've written, and I find that it's all worthless and should have been left unwritten. The things we achieve, whether empires or sentences, have (because they've been achieved) the worst aspect of real things: the fact they're perishable. But that's not what worries or grieves me about these pages as I reread them now, in these idle moments. What grieves me is that it wasn't worthy my trouble to write them, and the time I spent doing it earned me nothing but the illusion, now shattered, that it was worth doing."
Fernando Pessoa, The Book of Disquiet, ch. 169
So, I'm not the only one who thinks this as they write . . .
However, I think you can also read this on the broader, more metaphysical, level as well. Yes, Pessoa is reflecting upon writing, but he's also, in a sense, obliquely commenting on life itself. Was any of it worth doing? Like writing, life has only "earned me nothing but the illusion, now shattered, that it was worth doing." But you know, the thing about Pessoa is that, at least in my now multiple readings of The Book of Disquiet, he's not as completely despondent as he seems at first blush. I think he's disgusted and disheartened by the brutish coarseness of life, and thus maybe his inability to bring more beauty into the world. Again, at least in my mind, I think he's definitely inspired by beauty, driven by beauty, desirous of beauty, and in the end I think he achieves this on several levels (and through several heteronyms).