if you can keep a plant alive...

So I just finished house-sitting for friends for a month and I think I killed all their plants. They don't own pets, and the point of me being there really was to keep the plants alive. They mostly had cactuses, which makes my plant negligence worse. Reminds me of that Sandra Bullock movie where she's told when leaving rehab that if she can keep a plant alive for a year, she can get a dog. If she keeps the dog alive for a year, then she can consider dating. Maybe this is my dating problem: I can't keep a plant alive. Hmm. I'm going to have to think about this one....