In Log in^x, Past perfect^x

Unnecessary use of the Past Perfect is a common feature of English-learner speech. I understand the meaning is already pretty clear even without the use of past perfect, but what I wanted to know was which one would be the more correct one to use. I'm not an English-learner. I've lived in...

One of us is sleepy, Pieanne, but I don't know which. Why would I have moved from Yokohama after having just bought a house here? Why would Caesar's speech have to be brought forward to the 'present' tense? Factoid: MM bought a house last March. MM: I bought a house last...