Cogito ergo sum... If I am aware (or think as you say) that I am in a phone/computer screen, then I am literally doing it. This mechanism helps us (more or less) to understand what we are doing right now.
Also, when you say

. It is possible that you are dreaming the very same experiences that you are now having. — Aoife Jones

Not necessarily. I think this is why with our vocabulary we identify as "dreams" because somehow apart us from reality.
If randomly I dream something that I will experience in the next 4 days I would call it dejavou. Then, reality tend to be previously of the dreams we have

You just believe that reality is real. We are used to it. Although, it can only be a dream. Remember the philosopher ...

It is possible that you are dreaming the very same experiences that you are now having. — Aoife Jones

In your dreams!

Dreaming only makes sense in the context of wakefulness. I might dream that someone posted, " It is possible that you are dreaming the very same experiences that you are now having." and I replied, "In your dreams!" But that would only become meaningful to me if I awoke from the dream. In my dreams my dreams are reality and I am awake.

So it is never possible that I am dreaming, only that I have been dreaming. Only the awake can declare the dream to have been a dream.

So wake up!

Only the awake can declare the dream to have been a dream. — unenlightened

Except I suppose in the case of lucid dreaming , where one supposedly is aware that one is dreaming.

Webmd:

“ Lucid dreams are when you know that you're dreaming while you're asleep. You're aware that the events flashing through your brain aren't really happening. But the dream feels vivid and real. You may even be able to control how the action unfolds, as if you're directing a movie in your sleep.”

Except I suppose in the case of lucid dreaming , where one supposedly is aware that one is dreaming. — Joshs

Is it possible that I am lucidly dreaming you said that?

Even if lucid dreaming may an exception , I like your idea that to know you’re in a particular state of mind requires a second order reflection from the vantage of another state of mind. Do we know we’re daydreaming, or remembering , or visualizing while we’re doing it? Not really, because we’re busy being immersed in the details belonging to that state of mind. We can pop in and out of these states of mind , and note that we have been daydreaming or remembering, but true issue isn’t relevant to what we are attending to while we’ re busy performing these states. I could be totally engrossed in a movie and forget that I’m watching a movie foe most the time that I’m watching it.

It’s intrinsic to the style of experiencing of dreams that they are non self-reflective, so asking someone if they know when they are dreaming is kind of like asking them if they tend to be self-reflective when they are involved in non-reflective type of thinking. Dreaming is like being totally engrossed in a very long movie. Dreaming is about the opposite style of thinking from carefulself-reflection; it’s about impressionistic, sketchy , feeling-based visceral being. By contrast, asking me if I know whether I’m awake is akin to asking me if I can now perform a series of thoroughgoing acts of self-reflection.

To answer my own question, as one always must in a dream:- no it is quite impossible, because to lucidly dream is to be aware of the unreality of the experience, and since I am awake, or at least dreaming I am awake, if I am in fact dreaming it cannot be a lucid dream by definition.

The trick the op plays is to insert himself into my dream and try to make it lucid. but he can only do that for real in his dream.

Dreaming is thinking about the real world, just off-line and hence fundamentally confused about physics (the walking in the air).

On-line thought is fundamentally confused about psychology (the pictures in the head).

“4. Therefore you don't know that you are now sitting at a computer/phone screen.”

I learned how to sit, recognize a computer, and type out these words. Thus, I know now I am sitting at the computer typing. I am not dreaming such an event because I am not recalling something after I just woke up from sleep.

Good Night

Well that’s just an unproductive definition of the word “know”.

1. In the past you have had dreams where you were convinced of everyday facts like these, but it turned out that you were only dreaming them.

2. So, you can’t rule out the possibility that you are fast asleep and dreaming all this in your bed at home.

3. If you can’t rule out the possibility that you are not sitting in front of your laptop then you don’t really know that you are.

2. So, you can’t rule out the possibility that you are fast asleep and dreaming all this in your bed at home. — Aoife Jones

Yeah, I can. This is not a dream. It's too persistent, too detailed.

3. If you can’t rule out the possibility that you are not sitting in front of your laptop then you don’t really know that you are. — Aoife Jones

To know something is commonly held to be to have a justified true belief in it. It is fraught to think that my sitting in front of this laptop is justified... Justified by what? Hence you ar emisusing the notion of know. See Witti, On Certainty.

If we take a more lenient view of knowledge as the understanding of how things are that we use to act on, then I am indeed in front of my laptop typing this sentence.

But more generally, there is a point at which the sort of scepticism you wish to advocate falls over. Any scepticism is based on a presumption of other things being true. Even were this a dream there would still be a presumption of things such as laptops and web pages and typing and language upon which the dream relied.

3. If you can’t rule out the possibility that you are not sitting in front of your laptop then you don’t really know that you are. — Aoife Jones

That's correct. Could also be an evil demon or brain in vat.

https://thephilosophyforum.com/discussion/comment/515589

Uh huh.