Learn these technical skills within one day

Learn these technical skills within one day

It takes days and days reading books, practicing and involving in real project if you want to learn a programming language well. It's just like a marathon, you will get more if you can insist longer. During this long and boring period, there are always something
you can learn within a short period of time, like within one day. These skills can bring your big satisfaction.

Below are a list of technical skills which you can pick up within one single day, they are advocated by Jacob Jensen,  a Googler.

Read the freaking manual for your favorite language. In the past I've wasted hours in Python because I didn't know that the Counter data structure existed, and kept getting the bugs from using Dicts as Counters. There are many examples like this.
Get a stackoverflow account and learn to use the site. If you don't at least know that StackOverflow is an available resource, and you're an english-speaking programmer, you're doing it wrong.
Implement a simple Machine learning algorithm on your own, with a whole pipeline. I.e. you read a simple input csv, split it into training and test set, run a simple algorithm with readily-tuneable or explorable hyperparameters, and a simple output of relevant
statistics.
Learn the how to make a simple line graph in Excel, and make sure you can do it right; i.e. properly labeled axes and tick marks, title and legends.
Learn how to make a simple line graph in something other than Excel. Make sure you can do it right (same requirements).
Get your eclipse installation fully pumped up: python dev tools, c dev tools, any other language you could ever write in, and make sure you can write a hello world successfully in each perspective. It'll save you time some future day.
Learn the basic functionality of a NoSQL database; (you can learn a big chunk of mongoDB in a day)
Learn the most basic functionality of SQL (you don't need to be a query guru,  but have a small clue about it).
Learn a tool for in-depth parsing of HTML and XML
Implement a list-of-lists graph data structure
Implement random walk, PageRank, clustering coefficient finding (#triangles over possible triangles) and common neighbor number finding.
Implement BFS, DFS, Shortest Path, topological sort and Minimum Spanning Tree (bonus for union-find version). Take a couple days if you have no algorithms background.
Make a simple java applet that has at least some interaction with listeners and not just buttons and such.
So go and try out, you will be surprised of what you can do after one day's hard work.