The missing is the hardest part. No one is immune to it. During the holidays the missing is more intense. I don't know why it is. It just is. Those we've loved and lost always leave a space. At this time a year, that space can become a hole we fall into.
But most seem to navigate around it ok. Glasses raised and all that. Memories eventually coalesce around the good stuff. The pain is still there, but it's not quite an open wound anymore. It's been treated. Tears are replaced by twinkles. It's not so much about them being gone anymore. It's about when they were here.