Best way to find the moves in 1001 Winning Chess combinations and Sacrifices

Currently, I am working on building up my tactical skills and stumbled upon this book 1001 Winning Ches Combinations and Sacrifices: 21st-century edition from Chessable. It is quite a crazy book. Some of the moves are truly out of my range. What is the best way to tackle such tactics and find the best move like Reinfeld? Do I just have to drill them like using the 7 circle Method? An Example:

Do you have to be a robot?
  

Calculate all forcing moves. Your example is not that hard since Nc5 is the only sensible forcing move

Spend 5-10 minutes calculating forcing moves like checks captures and threats. No matter how suicidal a move looks at first, you should always consider it when solving a tactic puzzle, and just calculate it to see if it leads to anything... but again, checks captures and threats. So you're looking for loose king and loose enemy pieces.

 

If you can't solve the puzzle, that's fine. Make your best guess, write it down, and now check the solution. Now you'll have to spend probably another 5-10 minutes carefully going over the solution, trying to understand why it works. Also try to figure out why your best guess doesn't work. If you can't figure that out use an engine to help you. It's important to understand what you missed.

 

For any puzzle you didn't solve, make a note of it, and try it again later. Wait at least 3 days. If you fail it again, go through this same process again. Over time you'll learn new patterns and your calculation will become more efficient.

In Chessable you don't have to make a note on a puzzle that you got wrong, as Chessable works with spaced repetition. You will be soon prompted to solve the exercise again.

Dr Absolute, just make your exercises regularly, and make sure that you understand the combination. This is absolutely irrelevant hat you get the puzzles often wrong, and it doesn't matter that you are not able to calculate long variations.

But...

You have to be able to understand the combination after you saw the solution! And you have to go mentally through the whole combination and all variations after you saw the solution. This is crucial and will make you improve your visualisation and calculation skills.

For example, in the puzzle you mentioned a above you should be able to play the whole combination in your head. You have to understand why he combination begins with the key move (Nc5) and why every single move has to be played in this specific order.