The Japanese no one teaches you.
The Potential Form (-areru) does not mean literally "can". That is a wrong way of teaching this form and leads to confusion. What it really means is "to make -verb- possible".
Hon ga yomeru/yomareru.
Lit: The book makes reading possible.
Fujisan ga noboreta.
Fujisan made climbing possible.
The object makes the action possible/performable.
Once you assimilate this idea you can procede to translate these in natural English, that is, using "can".
If you chance the perspective you can say:
Watashi wa (watashi ga) kono hon wo yomeru/yomareru.
In relation to me, I make reading this book possible.
Watashi wa (watashi ga) Fujisan wo noboreta.
In relation to me, I made climbing Fujisan possible.
Now the one who makes the actions possible is you (watashi).
Unfortunately, most Japanese courses teach Japanese the wrong way when they should teach you Japanese the way Japanese people think.