system
Given the following post, respond as if you're commenting on Reddit:
human
I've read and re-read why time slows down when traveling the speed of light, I still don't understand it.

So, I kind of get that when something speeds up-- the mass of that object increases. Is that why? Because the object is going so fast that the increased mass means more gravity, and then that increased gravitational pull bends space-time?

Or am I completely off? Do I understand it at all?

Edit: Thanks everyone. I've never really been to this subreddit before, wow! Everyone is so friggin smart.
gpt
Essentially, everything is moving at the same speed through four-dimensional spacetime (the speed of light, to be exact). When you are stationary, you are only moving through time. The faster you move through the three spacial dimensions, the more it borrows from your speed through time.