Yes, but then poor Schopenhauer was a first-rate misery-guts. He claimed that the universe was evil, and that anything good was an illusion. He told everyone to avoid sex completely, live a life of poverty, practice a starvation diet, and practice self-torture. He didn’t have the guts to do this himself of course: he had numerous affairs, lived off a private income, dined well in good restaurants, and was as selfish as an oyster without an h. He once threw an old lady down the stairs.
Porcupines are only prickly if they don’t smooth down their quills. The quills are just a metaphor for our insecurities and fears. But there is nothing to fear in a nice cuddle and a nice soft conversation. And plenty of ways to maintain a sense of yourself (= to develop a love for yourself) without pushing others away. Schopenhauer thought we were all ultimately connected and one-and-the-same; but the poor old sausage thought that meant that we were all aspects of universal evil. But if you happen to think that love is good instead, then connection with someone else is a happy victory, not a painful defeat.
Anyway, why would anyone follow any advice from a man called Shop-opening-hours? We all know they are pretty limited.