I don't get this joke at all, please help

Factual Questions
1

I was told this joke today. I don’t get it and none of my friends do either. Perhaps somebody can fill me in on what it is I’m missing:

What do the thief crucified besides Jesus and Robin Hood Prince of thieves have in common?
The both sing “And I still haven’t found what I’m looking for” (U2 song).

…? WTF? Is this one of these things that just isn’t funny except for the one individual who told the joke?

I’ll now open the floor to interpretation.

2

To rephrase the joke, what did the thief crucifed beside Jesus have in common with Robin Hood, the prince of thieves?

I don’t get it either.

I found the lyrics here. The final verse has the lines

So, we know Jesus carried the cross … did Robin Hood break the bonds, or loose the chains[sup]1[/sup]?

Maybe someone else can explain it?

[sub][sup]1[/sup](or misplace them? :D)[/sub]