Hi Erica -
It is my perception that spontaneous occasions of lucid dreaming occur more frequently in younger people - ages 10-25 or so - than in older people. We most likely would look for a biological cause for this “window” of lucid dreaming. Certainly our hormonal systems are most active during these years, as we grow and reach sexual maturity, and this activity may account for more lucid dreams.
If you wish to regain your familiarity with lucid dreams, keep a dream journal and either write down or tape record your dreams when you awaken from them. Before sleeping, review some of the dreams in your journal and remind yourself to watch for your dreams during the night. Also, try using the “snooze” button on your alarm or clock radio. Because we dream very heavily in the early morning hours, the snooze alarm will most likely awaken you repeatedly from REM or Dreaming sleep, which will give you several opportunities each morning to remember your dreams - and to be lucid.
Please let us know if you try the above techniques and if they bring you success in lucid dreams.