"Everything gets harder if you start going on and on about how hard it is"
--Stephen Covey 

I tell my kids all the time to change their mindset.  To accept that some things are going to be difficult or scary and how they use those feelings will play a large role in the outcome.   I encourage them to use difficult things as a challenge, not an road block, and to use the nervous feeling as added positive motivation, not the usual negative connotation "nervous" is often associated with.