Diving head-first into a difficult problem makes a bad start
while you can Refer to advanced resources when skill-building for a solid short-term goal, a difficult problem is... difficult; you might see little progress compared to starting with a beginner's choice
you can always practice Switching between different topics makes new perspective between the two as Diving head-first with a difficult problem is a good indicator of progress as you make your steps
it can overwhelming with the amount of steps that you need to take
you can mix other problems that doesn't need to be there and difficult concepts essentially comes from understanding the basics
this is why you should Start small and improve later and Create roadmaps to stay on track to prevent forming bad habits in the first place