The initial simple loop is a fairly straightforward solve, like so:
![Solving initial simple loop](https://cdn.statically.io/img/i.sstatic.net/UH22X.png)
And once solved we can follow the instructions to read off every letter where the loop turns left, starting from the top-leftmost white square. This yields the instruction:
EACH COL ROW ONE IS LYING
With thanks to @user39583 for their comment on @BeastlyGerbil's answer, this suggests that:
In every row and column there is exactly one square that is incorrectly shaded - i.e. a square that is white that should be black, or vice versa. We should then be able to resolve the simple loop another way.
So let's give this a go... Throughout the description that follows, I will shade squares light blue if they are a correct path space or dark blue if they are a correct blank; purple will equivalently be used for the squares to be altered.
Step 1:
First, focus on the edges:
Bearing in mind that we cannot leave any edge path spaces isolated between two blanks we can immediately identify many path spaces and blanks that must remain so:
![Step 1a](https://cdn.statically.io/img/i.sstatic.net/fqSYC.png)
Please excuse the artefacts - this is a rough MS Paint job...
We then spot that the incorrect spaces in columns 4 and 7 must be in rows 1 and 10, since there are only two complementary possibilities for the incorrect squares in these. Furthermore, the squares diagonally adjacent to each of the four grid corners must be path spaces for the loop to continue.
![Step 1b](https://cdn.statically.io/img/i.sstatic.net/xbZie.png)
Step 2:
Let's start drawing in the loop now...
While doing so, we can see that the loop must pass straight through the spaces in R3C4 and R8C4. Also, the 'A' in R8C9 and the 'I' in R6C2 must be correct path spaces to avoid isolating neighbouring cells.
![Step 2](https://cdn.statically.io/img/i.sstatic.net/Ez9jq.png)
Step 3:
Focus on the bottom-left corner of the grid:
The 'L' in R8C2 must be a correct path space - if it weren't so, the 'D' above it would end up isolated if the 'H' below it links in turn to the 'S' and 'I'.
Now, the 'S' in R9C3 must also be a correct path space - otherwise, ultimately either the 'D' or 'I' in column 2 would need to connect to its right through column 3, via an incorrect blank space switched to a path space, but the column 3 incorrect space would already have been taken by the 'S'...
Once both of these spaces are marked as correct, we cannot link the adjacent 'H' and 'S' in row 9, as the 'S' would then need to link to the 'I' above it and the 'L' in R8C2 will be stranded. There remains only one way to resolve the loop in this corner:
![Step 3](https://cdn.statically.io/img/i.sstatic.net/H3qDe.png)
Step 4:
This now means we can identify our first incorrect spaces:
R10C4 must be a correct blank, so the incorrect blanks (which should actually be path spaces) in rows 1 and 10 are in columns 4 and 7, respectively.
![Step 4a](https://cdn.statically.io/img/i.sstatic.net/4m3mY.png)
The shape of the loop at the top now means it is impossible for the 'F' in R2C5 to be included in the loop - it is an incorrect path space and should instead be a blank. All other cells in its row and column can be marked as correct:
![Step 4b](https://cdn.statically.io/img/i.sstatic.net/G3t4e.png)
This in turn means that R3C6 must be an incorrect blank that must actually be a path space in order for the loop to continue:
![Step 4c](https://cdn.statically.io/img/i.sstatic.net/noqaZ.png)
Step 5:
We can now see where the incorrect spaces in columns 1 and 2 lie and resolve them:
![Step 5a](https://cdn.statically.io/img/i.sstatic.net/STsaC.png)
Then R5C3 must be a path space (not a blank), which means only one possible incorrect space remains in column 9: the 'E' in row 7. This in turn fixes the final two incorrect spaces (R8C10 and R9C8):
![Step 5b](https://cdn.statically.io/img/i.sstatic.net/GQcb8.png)
All that remains is to complete the loop through knock-on deductions, eventually reaching the following final state:
![Step 5c](https://cdn.statically.io/img/i.sstatic.net/cUZvu.png)
What next?
Now to read off a new message, but this time in the opposite way to what we did the first time around - taking the letters where the loop turns right, as per the last line of the poem ("Right now, yes, right now"). This one reads:
PENS PRETTILY AN UGLY POEM
![Extracting the letters](https://cdn.statically.io/img/i.sstatic.net/whJID.png)
So does this give us a clue to answering the OP's ultimate question: Who is he really? Well, a potential solution (suggested by @DanielS in comments) is:
The poet Abdullah Shoaib, who wrote a poem called 'Pretty Ugly' which went viral in 2018, as it is a reverse poem, i.e. one which after reading it from top-to-bottom can also be read bottom-to-top to give the reverse sentiment. (In fact, this is a trick I employed myself in one of my very first puzzles on this site, which was itself inspired by two other reverse poems I had come across...) This 'reverse poem' nature is also exhibited by the OP's own poem beneath the grid image (try it for yourself and see...), so everything is tying together here thematically.
In fact, if you mark all the spaces in the grid which were used in either of the two messages we have found so far, the leftover letters spell out for us that THE FINAL ANSWER IS ABDULLAH SHOAIB! And the puzzle is solved good and proper!
![Hidden message revealed](https://cdn.statically.io/img/i.sstatic.net/vCuk7.png)