Do i need to memorise everything?

I’m 9 days into the Data Science career path. I’m not having trouble understanding and completing the lessons as i go through them but i do find myself referring back to the lessons whenever i’m doing the code challenges or projects to see how certain queries are correctly typed or how they work etc. to be able to solve the challenge or complete the project (I print out every lesson and have it ready by me every session i continue the course)
I’m curious, am i expected to know everything by heart to be job ready?
Do i need to practise it all, as much as it takes until it all becomes second nature before i can consider applying for a job?

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Programming is problem solving. Teaching yourself to solve a problem by breaking down the problem into small steps is very important. First solve the problem, then write the code.

Sure, you need to know basic concepts (loop, functions and more), but you will see that many programming languages share these concepts, so once you are familiar with these basic concepts, learning another program language becomes a lot easier

I still regularly consult documentation. Teaching yourself to read documentation and quickly find what you are looking for is really useful. There is simply too much to remember, and sometimes you work in languages/frameworks/libraries you don’t use a lot, then documentation is really useful.

Just keep practicing, make projects to build a portfolio, learn some algorithms (merge and bubble sort for example), be curios, ask questions, keep learning and improving.

hm… i might need to restructure my answer. Hopefully there some good and useful bits in there for you :wink:


Hello! I used to develop Java software professionally. No, you don’t need to memorise everything!

I had a massive Java reference book on my desk. I referred to it very often, when I was looking for a method I hadn’t used before (or often). For example, I’d say “Hmm, I wonder if there’s a method for manipulating strings in this way, or that way…”, and then I’d look up the String chapter to see if there was a method matching what I wanted to do.

I couldn’t memorise every single method! I did find, however, that I did end up remembering the methods I used very often. So, after a while, I consulted my reference book less and less often…

Therefore, the key is to write as much code as possible; do as many projects as possible. Then, as time goes by, you’ll find that you’re memorising your most-commonly used queries without even trying.

I like that you’re printing out the theory and referring to it. This is similar to what I do - as I progress through a lesson, I type handy functions into a Google doc that is open in another tab. In fact, I have two notebooks full of summaries I created when I did a web development intensive last year. I’m so glad I wrote all that, because I recently got back into it, and I read through those notebooks to refresh my memory. I’d be so lost without it!

Good luck with your studies! Once I brush up on my web development skills, I’ll be joining you on the DS path!! :slight_smile:


I have been coding for years. However, I cannot remember everything, even ones that I have used. Sometimes I have to search again for the syntax error, some of them are errors that I searched on the very first day.

Don’t worry if you cannot remember the syntax. Programming is problem solving, not syntax remembering. You can forget the syntax, as it can be easily found on the internet. The important thing is how you solve the problem (approach, time complexity, variable names…) that makes the program runs efficiently.

Happy coding~!