What makes you think so?
Personally....and I am rather insulted at this thread's assumption (so far, at least) that it is only selfishness (or 'ego') that wants to live forever.
I don't want to LIVE forever. I want to LEARN forever. I am not so imbued with a sense of mankind's modern sense of superiority as to think that we all know everything and that living longer than a mortal lifetime will result in boredom. I look at the universe...and I'm having a little difficulty imagining that there will ever come a time when I will know everything there is to know, and will have done everything there is to do.
Or understand all that there is.
My own time on this planet isn't going to be all that long. For crying out loud, even if I did NOT have cancer, I'm almost seventy...and trust me, I ain't bored and if I were going to be given more time, I would still not be bored.
Depressed, angry, joyful, nervous, frustrated, annoyed and annoying...but never, EVER, bored.
It's not 'ego' that has me wanting resurrection and eternal life. It's curiosity.