No it isn't bad, and no you aren't weird! We all grieve differently. Also some of our pets although we love them all, just leave greater impressions than others. I lost one of my favorites piggies, Pirate and the most wonderful hamster, Travis within the same week 5 years ago. In September. Every year since then I will think about them both through that month. I was that devastated over Travis that the two hamsters I've had since I have barely bonded with, I obviously cared and provided to their needs. But I didn't love them. I've had piggies die since then and i couldn't say exactly when they died. But those two little animals were so close to my heart. I have loads of photos of Pirate (and his friend Pickwick) around my room and I kept Travis's favorites house. I went to donate his things to an animal charity but couldn't leave it and left crying! In fact I can only just look at baby hamsters that look like him without blubbing!