not retaining RAM data

Hi, I am experiencing problems with my mac. I have not been able to have it retain data from browsing sessions or recent content. This happens any time I shut down, log off, or restart the computer. This is a pressing issue as I am a developer and I require my most recent files to show when I click the file>open recent it shows things that were opened over a month ago instead of a day or two ago or the most recent files that have been opened.

thanks in advance,

Brett