Why do I worry?

Clearly of the pair I am the worrier. My husband is like a surfer dude. He is so calm and cool about every situation. Like all that really matters is catching that next big wave. This is why we go together. He balances my worries.
Today I took Bunnie to be spayed. I know it is a standard procedure, but any time an animal (or person) is put under anesthesia there is that minute chance they won't wake up. I'm trying to stay calm. The other three furry monsters met me at the door when I returned from dropping her off. I'm not sure if they knew something was different, or they were just waiting for breakfast. Probably the latter. Usually she is in the same room as me all day. So now, even though I have three others in the house (somewhere), I notice her absence.
How odd is it that an animal can capture your heart? They've all got me wrapped around their little furry paws. But I like it.

UPDATE 2/6: Bunnie is feeling just fine. She was a little strange when we brought her home. The other cats didn't recognize her scent so they hissed at her and she hissed back. She was pumped up on pain meds and very hungry. I took her to bed with us last night and she never moved from the spot. She also snored at which point I thought "Great, two noisemakers in the bed!" but I got over it.