We are what we do and often while doing a gazallion things, we do a thousand things wrong which leads to a thousand learnings as well. I am documenting my learnings here so that you don't have to commit those:

1. Buying old physical technical books - Technology gets outdated mostly in years, therefore, don't buy old technical books for personal use if the technology might have gotten outdated and the book contents may not hold relevant for the prevalent technology of that time. For example: To save some monies, you bought Python 3.2 book but the current stable version is Python 3.8 which has substantial changes in way particular function worked or coding is done. The book may not serve the required purpose.

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