Hi Illya,
I agree by moving out of your comfort zone you do learn more, it presents a challenge, and we all need to be challenged. The security is that you have control which direction your learning will take and how far you will proceed. I guess knowing you are in control of these parameters gives you a degree of comfort about learning new things. I think if someone insists you learn this in a particular way it is easy to turn off & not learn at all because you are restricted & as a result there is no challenge.
Cheers,
Vida