How many 45min sessions to do in LMPTHW?

I got LMPTH 3 weeks ago but I think I’m spending too much time on the 45 minute drills.

For example I spent 1 week cloning cat perfectly then I’ve been working on grep for the past 2 weeks.

In the study drills, Zed said to try to spend more 45 minute sessions hacking on the projects but I can’t seem to stop until I get the perfect implementation.

It’s fun but am I doing this right or should I just move on to the more advanced stuff now?