Axure People are dead forever. Just because people don't talk about them all the time doesn't mean they don't miss them.
Maybe the "attention seeking" and cancelling arrangements are moments when they remember them so much more.
For example, you arrange a party for all your friends, your friend who has lost someone will then be thinking, if x where here, they'd be coming too and so they are sad that their life before has changed. Therefore they mention how much they miss them at that time.
I had something booked last weekend, it had been arranged for ages, he wasn't going but it was connected to something that he is invited to, I didn't want to go. I dd go, I had a nice time but I thought about him most of the time and didn't enjoy myself like I would have, had he not died. I didn't tell my friends because I didn't want to take away from their day and happiness. Thankfully, they all could tell and although we didn't talk about it (and start me crying) they kept me company and distracted me.
This probably doesn't really make any sense, I know what I want to say but the words won't come out right. I swear when I found him, something shorted out in my brain and now I can't keep a cognitive thought in my head! I did also mean to thank everyone else, including Northernlurker, in my thanks for telling me that it is ok to grieve anyway that helps.