Mom Clearing away my Things

My mom is taking everything personal out of my room. My clothes can stay and so can furniture but everything that is mine - photos, memorabilia - has to go. I get into an argument with her. This goes on for a while. Finally, she tells me that she is showing the house (for sale) on my birthday. This doesn't hurt my feelings as much as I thought it would. I tell her that all she had to do was tell me and I would have moved them for her.