请问下面这则幽默究竟是什么意思啊?看不懂

请问下面这则幽默究竟是什么意思啊?看不懂
As a child,I could always depend on my father to put life's disasters into perspective,whether it was a broken leg or a broken heart.Years later,I was devastated by a series of personal crises.Feeling helpless and overwhelmed,I spent my last three hundred dollars on a trip to Florida to see Dad.
On the final evening of my visit,we stood at the end of a jetty watching the sun settle into the Gulf of Mexico.I could no longer contain my bitterness.
You know,Dad,if we could take all of the great moments we experience in our lifetimes and put them back-to-back,they wouldn't last twenty minutes.
He responded simply,Yup.
I turned to him,stunned.He was still studying the sun that sat on the horizon.Then,looking evenly into my eyes,he added quietly,Precious,aren't they?

小时候,我能一直依赖着父亲,生命里的那些困难,从脚伤到心碎,都似乎离我很遥远.好多年后,一系列的个人危机把我打垮了.感到无助和巨大的压力,我花了仅剩的三百美元去佛罗里达看父亲.我旅行的最后一个晚上,我们站在码头上看夕阳渐渐沉入墨西哥湾.我再也无法抑制自己的痛苦了.
“你知道的,爸爸.如果我们把我们生活中经历过的所有美好的时刻一个紧接着一个地像cd一样放映一遍过去,绝不会超过二十分钟的.”
他回答得很简单,“啊!”
我转向他,很震惊.他仍然陶醉在倚在地平线上的夕阳里.
然后,平静地看着我,说,“很美好,难道不是吗?”
这应该不是幽默,如果非要说是幽默的话,只好说是有些双关的手法,美好既指夕阳,又指生命中的那些时刻,虽然短暂,从而唤起作者的希望.