I... I just learned that 'now' doesn't exist. For more factors than one.
We view 'now' as the time and place you are currently in. So if you stopped time, that would be your 'now'. But for someone else, that is not 'now' that is 'then'. 'Now' is relative, it's impossible for people to experience the same 'now'. Like let's say you have a strong telescope and you're watching someone on say...Kepler-1606b. You would see them doing something, for you this is what is happening 'now' but due to the speed of light and the distance, that person is actually in the future. You don't see them as they are, you see them as they were. For all you know, a black hole could have opened and that person wasn't there anymore. So this isn't really 'now' it's 'then' in the past and the other person is 'then' in the future.
Let's say, you know everything happening in the universe right now. Every quark and atom in the universe, you know what it's doing or where it's moving. You could use that information to predict the future and even change the past. By all accounts, you'd basically be a god. So then surely, you should know when 'now' is, right? Actually, no. Now is different everywhere in time and space. Now is a non-existent subject. No place in the universe has the same 'now' as somewhere else.
An experiment was done once, these scientists put clocks on two commercial airplanes and each one went around the world twice, once eastward, once westward. Afterwards the clocks were compared with ones that were stationary and suddenly, the three clocks couldn't agree on the time. They didn't glitch. They kept record of time perfectly fine. To each of those clocks, that time is 'now' but they don't have the same 'now' so the 'now' you experience isn't really 'now' but rather 'now' you know?
Now is always changing. By the time you think of 'now', 'now' fell down a well. It's impossible to purposefully think of 'now' exactly down to the quadrillionth of a millisecond. 'Now' will never be 'now'.
Your brain keeps track of time, from the moment you're born, your brain counts the seconds that pass by. But that isn't 'now' that is only 'now' for you. No one else, not even your twin, has the same 'now'. Your brain itself doesn't even know 'now'. Time is a non-existent concept of time and space, which we use to give us comfort in our lives and to feel the time pass so we don't drive ourselves insane from not knowing when is now then or later or soon. It's just a lie we tell ourselves for our on comfort and to make us feel important but in the grand scale of things we are but a spec of dust in the universe, time is a pointless measure that we homo-sapiens came up with to find a true meaning to everything when in fact our only purpose is to die and either spend eternity in torture or in blissful harmony. Either way, it's the end of our time on Earth which just means it's all pointless and nothing matters.