riddle - I tend to forget things

I tend to forget things. The only thing that keeps my memories alive is dreaming. During the day I listen to all that is said to me, but in the evening I already forget it. But when I fall asleep all that I learned that day tries to make it to the surface of my conciousness in some enigmatic form. I will tell you my dream. Could you remind me what I forgot about today? Otherwise someone will certainly be mad at me tomorrow.

My drawing skills are not that good, but I will try to draw you some outlines of my dream. To make sure you understand it see the description below:

The question is: Could you remind me what I forgot about today?

Credit (but also a hint):

This puzzle was inspired by (the mechanics of) this great puzzle by Ankoganit.

Answer

I followed the riddle about the dragon and got a result of

'drAgN' (capitalised parts were described as larger and the o is the crushed 'hole').

I used a

Vigenere shift with that as a key using the order of lowercase uppercase and numbers provided by @M Oehm commented on the other answer.

This led to the following page:

https://i.stack.imgur.com/QHPzy.png

From there much of the labarynth is visible including the key

'd6AQ5'.

I then decrypted the door on the right at the start with that key and the key

('dream')

which I got from the hint that the key is

('what this is all about')

leading to a result of the page

(https://i.stack.imgur.com/R657h.png)

From the clue

(about going to 'his or her door':)

We know

(that they forgot about going to visit someone.)

From the clues

(about the shape of the puzzle and about the watch being stuck at 5pm:)

We know

(that they forgot about having tea with someone because 5pm is tea time and the puzzle is in a 'T' shape.)

From the clues

(about it being somwhere 'near you and my ant':)

We can get the word

('aunt'(by adding 'u' to 'ant'))

Putting it all together, we can work out that they have forgotten about their plans to

have tea with their aunt.