I just bought the new 2015 macbook pro retina 13 inch 8gb. I am new to mac and noticed that memory used was at 7.99 out of 8 gb on activity monitor and kernel_task was the highest. The memory pressure is low (low Straight line) green and there no other issues. I ran diagnostics but don't see anything wrong. When I restart and close some items it goes back down to 3 - 5 gb. I have no installed programs like google chrome on my mac. I've read some articles that this is normal but wanted to get everyone's opinion. Thanks.