Cats know how you feel. They don't care, but they do know.
I've had cats most of my adult life and can honestly say I have never owned a cat I didn't love. Some have been more loveable and some less so, but they all have a place in my heart... even if they care how I feel. Generally speaking though I think they could care less whether I come home or not as long as they are fed and have a clean litter box.
All cards are blank inside so you can express your personal wishes and come with a matching colorful envelope.