Aiming too high IS a mistake!
Why? Because too much discipline actually kills the fun and excitement you might have about a topic.
Most topics have something interesting about them.
It simply depends on the angle or how you approach it.
Too much discipline requires too much will power and will power is something you can run off.
Instead, choose a study rhythm you can easily maintain without major effort.
That's the ideal goal!
I know... Sometimes you are pressured by time and you need to boost your productivity and study long hours.
But guess what? Usually, that's something you can predict, so plan ahead.
If you start early on a topic the mind sets associated with it are integrated in your mind progressively.
Give yourself space and time