I read long ago about an airline company that took the effort to make sure the final moments were pleasurable because they had discovered that they were rated higher if they did that.
If you have a newborn, it is an exhausting experience initially, but you forget that later as you have wonderful times with your child. It is good you forget because otherwise, no one would ever contemplate taking a second child!
The ‘experiencing’ brain versus the ‘remembering’ brain. While we do something, we ‘experience’ it, but our brain only remembers highlights and the end afterward.
This matters for drawing. Drawing can be fun; it can be slightly less fun occasionally when you need to do things you don’t like. I wouldn’t say I like drawing perspective lines, for example. It is okay if not every second is joyful. Do make sure you enjoy it most of the time, though! Otherwise, why do we do it? But if you end up with a result that pleases you, you remember that, and you will be more excited to draw the next day.
So, if you just drew something beautiful or finished a nice-looking sketchbook page, consider stopping there! Consider adding another drawing session later, but celebrate that success and enjoy it! Let that be the thing your ‘remembering’ brain remembers.