it's kind of life changing when they leave us, because our entire lives revolve around them, just as you've pointed out in your post.
It's amazing how these little furry creatures take up so much of our time...and we're good with it.
You gave Leo a chance when he needed it and he gave you purpose and something to dump all your love on.
That last bit...Dad is a fantastic father, and I *know* beyond a shadow of a doubt that he loves me very, very much. But he's not big with the hugs and kisses and actually SAYING "I love you". OTOH, Leo was always up for a good cheek rub or belly scratch (I still think it's a little weird for a cat to want his belly scratched but it's not as uncommon as I thought it was) and would, till the end, rest his head softly in my hand and physically express his love and gratitude for me.
you may even want to wrangle Juice into a hug if you see him, it might make you feel a teensy bit better.
Ah...I wish I could. I may not have mentioned this here but some time in the fall, Mr. Juice went outside and never returned home. He is chipped, so the odds of him finding another family are pretty slim :-(