Create contact notes and journals.

Keep a note and a journal on your friends or customers.

Have you tried borrowed something out to a friend and then forget who it was.
With Contact Journal you will never forget something like that again, just write it in the journal and you don't have to be in doubt.

If you have a company or are working in any job where you like to remember even the smallest details of your customers/clients, just write it in the journal or make a note so you can pick up where you left them the last time.