A real-life question full of meaning and emotions that one would be able to pose to his or her beloved or sweetheart. Between friends, the meaning would be slightly different.
Like many, I haven't uttered the exact words but something less exciting. It sounds good in movies and maybe in life when a couple is in love and the boy/ girl proposes, he can use this phrase. In real life, there would be many situations in families where such lines would pass unspoken between them. A couple for the first time being aware of their first child share a few moments of joy that would be etched in memory without so many words being said. The joy of beholding their children, sending up to school for the first time all these are treasurable moments that would echo the thread's meaning.
Similarly when calamity strikes, when there is a financial loss, career setback, major illness, these are testing times where the couple depends on each other for moral support and manage to survive the bad times.