I meant that you tend to spend free time on that as opposed to treating it like 9 to 5 job. and again it is important that if you do that, it is because you just want to see what comes out of your experiment/learn a new thing etc rather than because you have to publish or is forced by your advisor.

I see. I think I definitely lean towards that.

You'll do great. This will eventually turn into new discoveries if you keep at it.

That is the hope!

Why not just study a bunch of different things to Master's level then? Learning something genuinely new seems like it has a much lower return to effort.

Good question. IMO

1) There's a kind of "hard" learning you're learning a fixed, structured way from a textbook.

2) There's a kind of "soft" learning which is transmission of knowledge, which happens a lot more face to face when you're working together.

3) Then there's a kind of research learning, where you're doing something new, usually with collaborators.

The second and third are really best done in certain environments like research or good companies