I know our perception of time as being linear is not a reality. I feel this may actually be one of the largest things humans need to acclimate to when the prison walls come down. Personally, I found it helpful to start with how different cultures perceive time before trying to understand upper dimensions of existence. An old article I like on the subject: https://www.businessinsider.com/how-different-cultures-understand-time-2014-5?r=US&IR=T

After you're done with that, try to wrap your head around this:

What do you mean by linear? Are you aware that linear doesn't mean straight?

Regarding the video:

Imagine a 2D being in front of you. Draw a figure on paper if you can't imagine it. Then draw a line from left to right. That line is representing the timeline of the 2D being.

Now branch the timeline. You, as a 3D being, should be able to do that, right? How would you do it?