understanding the true character of someone or something.
I knew Bill for a long time, and I went into this relationship with my eyes wide open.
with (one's) eyes wide open
With full awareness. I know they're offering you a lot of money, but make sure you go into this situation with your eyes wide open—it could be a scam.Considering John's history of infidelity, Claudia knew she could only take him back with her eyes wide open.