Well, since all roads lead to death, life is a joke, and it's a joke that everyone will tell in their own way, but the punchline remains the same in all cases. You die. The answer to your question, then, is that life is simply death in a clever disguise. Don't be fooled.
Is that you Schopenhauer?
Seriously man, lets see..what is a joke? A joke is largely defined as something that is perceived to be a surprise. Something you didn't know and/or realize you knew before. I think there might be something a little more as well..to be a joke, the feeling associated with the surprise has to be at the worst irony, at best elicit the good feelings of laughter..
The other use of joke is that something isn't all its cracked up to be.
So, except for the really dim witted and small children, the former isn't really applicable (and I include the religious here as well just for kicks - even though they think we "keep going" after death.). And the latter is only applicable to those who for whatever reason thought that life was going to be "something different" or perhaps that death was to be "achieved" in a different manner.
So, life really is only a joke (in the latter sense) to those that think about it as a joke. Why? Because for there to be a joke, there has to be a perceiver of that joke via an understanding that life is as you said. However, this is not logically necessary.
There can be a perceiver of life that does not think it is a joke. So what tips the scales over in your favour?
You seem to have based your idea of life being a joke based on the fact that death is at the end. You have a long way to go to show that these two facts are so interrelated so that life is indeed a joke regardless of the frame of mind of the perceiver and gives one perception more weight (or all the weight!) over the other..
life is simply death in a clever disguise
I would say life and death are "change". Whether they are the same or not might depend on your point of view. To us humans, they are different. It is unknown outside of our humanity what idea(s) of life and death might present to that unknown mode of being..
I would submit with Cochran that life is a highway and I want to ride it all night long..