ANY MODULE IN SAP IS VERY VAST HENCE IT IS VERY DIFFICULT TO DO ALL THE THINGS AT A TIME AND REMEMBER EVERYTHING. IT IS ALWAYS ADVISABLE TO ADOPT A STEP BY STEP POLICY WHILE LEARNING SAP.
FOR EXAMPLE WHEN YOU DOING GENERAL LEDGER IN FI DONT TRY TO JUMP FROM G/L TO ACCOUNTS PAYABLE OR ANY OTHER TOPIC. TRY TO LEARN THE TOTAL IN AND OUT OF GENERAL LEDGER AND THEN TRY TO TOUCH THE SECOND TOPIC.
KEEP SOMETIME FOR EVERY TOPIC AND TRY TO LEARN IT IN TOTAL WITHOUT SKIPPING EVEN A SMALL TOPIC.