learning

• You can't teach an old dog new tricks

  It is difficult for people to change their established habits or learn new things, especially as they get older.

• To have one's eyes opened

  To realize an important truth or understand something new, often after being previously unaware.

• Tabula rasa

  A tabula rasa refers to the mind before it has received any impressions from experience, or a clean slate ready to be filled.