If you could go back in time and redo one thing in your life, what would it be?
Regrets, it seems, are easy to realise when you're dying.
If time travel is possible, where are the tourists from the future?
If you see an antimatter version of yourself running towards you, think twice before embracing.
That's just how time travel looks like to the untrained eye. The reason why there aren't more travelers is that your average physicist refuses to be eaten by a giraffe in the name of science.
The bottom line is that time travel is allowed by the laws of physics.