As you well know, you are now suffering the effects of poor study habits in HS. You now don’t know how to study and retain information.

One thing that helps a lot is to write down key points as you study the text. Not everything, but those things that will help you recall what the text is saying. Writing things down helps retention a lot.

Another helpful technique is to discuss the subject matter with others in your class or with friends. This helps you with retention and also gives you other perspectives on the material being taught.

Discover your key productivity periods and places

Morning, afternoon, or evening? We are usually best at a particular time of day (or night).

The website below may help too. It has more tips but you need to study it too.

I am glad to see you are now planning to study. Don’t get discouraged. You may have to work extra hard at first, but eventually you will find it easier to retain info.

Added another web site too. It’s an on-line (free I believe) course on How to Learn with audio or print versions.

writing down does help. But don’t just copy when you make your own notes!! That would be pointless. Try to rephrase what the textbook is saying, while retaining key words and concepts, so you understand and remember it. Perhaps you could draw mindmaps to illustrate key concepts to yourself. Or after you read every topic, come up with your own questions for each section and answer them without looking at the text first. Sometimes, it is also useful to draw diagrams, especially for subjects like Biology. Personally, I like to draw up tables that helps me compare two or more things that I’ve learnt. For example, I have tables that help me differentiate between the endocrine and nervous system, etc.

The key to remembering your work is not based on pure memory alone, I think. So when you read your textbooks, don’t just read it like a story book because the language used in textbooks is very specific and even deliberately complex! It makes memorising it difficult and horrible! Always internalize what you are reading. I think this is best achieved by putting in your own words what the text is illustrating to you, and answering questions that you’ve set for yourself.

I hope this helps!

write things down, it helps with your memory.