I think the most difficult of the 5 senses to live without would be sight. However, I know that many people are capable of living completely normal and happy lives even without having all 5 senses. I have always found it interesting that if someone loses one of their senses, the other senses become even more power to help compensate for the loss. It's incredible how the body works! I have a deaf dog and his sense of smell is UNBELIEVABLE.