If I had a time machine, I'd visit Marilyn Monroe in her prime or drop in on Galileo as he turned his telescope to the heavens.
One, remember to look up at the stars and not down at your feet. Two, never give up work. Work gives you meaning and purpose and life is empty without it. Three, if you are lucky enough to find love, remember it is there and don't throw it away.
I have so much that I want to do. I hate wasting time.
There is no unique picture of reality.
Even if it turns out that time travel is impossible, it is important that we understand why it is impossible.
Theology is unnecessary.