Is concurrency hard?

[Micky Latowicki]

Hi all. I'd like to tap on your wisdom and experience regarding a general 
question. 

Is concurrency inherently hard?

I've seen it stated elsewhere that writing concurrent software cannot be made 
easy. The author was writing in a context of a very different approach to 
concurrent programming than erlang's and I was curious if erlang developers feel 
the same way. If so, then what's hard about it when working with erlang?

Thanks in advance for your input,

Micky