my teacher has asked me to collect my things when he found out I was going to be moving schools

I just moved to a new place and I'm supposed to start school tomorrow. I told him my teacher that I was moving to a new house so I will be leaving the school after summer break. He got a little mad and asked "when did you find out? Did you know about this the whole month of MAY?" I got a bit taken aback but said yes. He said okay well go collect your things. I'm soooo confused.