I am an absolute neophyte regarding physics. What are the challenges to achieving it?

Note: As I am a physics neophyte, an answer a layperson can understand would be appreciated, if possible.

I'm not sure this is a duplicate of [Why is cold fusion considered bogus?][1], because that question is talking largely about the validity of some claims of cold fusion being realized. This question is specifically asking about the challenges of cold fusion.


NOTE: I am not asking how to achieve cold fusion, I'm asking about the problems encountered so far.


  [1]: http://physics.stackexchange.com/questions/3799/why-is-cold-fusion-considered-bogus