It is a visual diary because of the EXIF data in the photo. Helps you to recall what you bought or what places you went to on a certain date. Especially the simple camera on the mobile phone since it is usually with you. Great for recording receipts and small documents on macro mode. That explains Nokia's market share crashing down after they disabled close-focus on their mobile phone cameras.
$$$ can improved the quality of life. A small camera can slightly improve quality of life but not for long.
Health and happiness can improve for longer period of quality of life, besides passion for camera. A string
of owning large cameras can give more joy but it is not everlasting. Developing a lifetime passion as a pro
and as a career photographer can help to give a better quaiity of life. As a hobby, it helps to occupy the mind
and time temporarily due to diminishing return of the pleasure derived from possessing them too long. There
is always the desire to buy new products when they are launched.