Hmm......from what I remember ,HF True Ending Epilogue ,when Rin, Shirou, Sakura, Rider go to watch the Cherry Blossoms.
Life is but a River.
A continuous flow,relentless till it reaches its destination.
Rocks,rapids,falls hinder not the flow of the strong.
It has its ups,and its downs.
And in the end,peacefully.......
It dissipates into to vast Ocean.