Dawn on
Definition 1 of 1
Pro Tip 1/3Sudden Realization
The phrase often highlights a sudden moment of understanding, as if waking up. 
As the teacher explained, it dawned on me how the equation worked.
Pro Tip 2/3Not Immediate
Understanding can take time to develop, not always an instant realization. 
Over coffee, it slowly dawned on us that we had met before.
Pro Tip 3/3Personal Insight
Use when the realization is personal or specific to the individual's perspective. 
After our chat, it dawned on her that self-care is important.