Normally 'they' say "Make your tenses agree!" OK, but I read the following first-person description:
“Alex had explained, and I am content because of it.”
The “I am” should be “I was” by the above rule – but no: she became content, is content, and forever will be because of the explanation. The sense wasn't just that she is currently content, but that it would span the future as well.
What is this form called? It's not past-, present- or future-perfect: is there infinite-perfect?