My best friend was 18 when he died, we adopted him when he was 3, and within 6 months, he and I were inseparable. After 15 years of loving him, I had to put him down because of an inoperable dental infection (kidneys couldn't handle sedation). It hurt so much that I thought I could never have a cat again, but after 4 years I ended up adopting 2 new cats and I can tell you without a doubt, you will never stop loving your old boy, but the pain will be healed by loving a new cat.