Reflect upon is an expression that encourages one to think deeply and carefully about something. It can be broken down into four crossword solutions: CONSIDER (8 letters), REVOLVE (7 letters), bear in mind (10 letters), and CONTEMPLATE (11 letters). CONSIDER means to think about or examine something carefully, while REVOLVE implies to think about something repeatedly. Bear in mind suggests to remember something, and CONTEMPLATE means to think deeply about something. Together, these words suggest that one should take the time to think deeply and carefully about something, and remember it.