Motivating students to push their limits I think I must be stranger than usual sometimes, I always seem to take on topics that are somewhat more difficult than the mainstream, in very trying conditions - but the outcomes are very much worth it (not for me per se, but the benefits for everyone, potentially).

I try to instill this in my students, by 'gently' mentoring them and encouraging them to push their own limits a little further each time.  Also, I teach them that 'failure' is just another step to success.  For the most part, my students take on the challenges and the work, ideas and enthusiasm from them, frankly humbles me.

However, I am always wishing to learn new techniques to encourage my students to push, and even exceed their limits.  

What strategies are most effective for encouraging students (and colleagues for that matter) to take on the difficult topics?
The most important aspect is the teacher's attitude. It sounds as though your students are already benefiting from yours.

As @Cinco says above,


  motivation is not a static, unchangeable property of particular students... A good teacher arouses the motivation indirectly, by creating the right environment for learning.  


Based on my experiences with some awesome professors, I will say DO


hold your students to high academic standards.
assume that the students are capable of doing more than they are currently doing.
show them how the subject you are teaching is relevant to them.
be enthusiastic.
recognize their great work, and always expect more and better in the future.


Perhaps most importantly, have fun! Enjoyment is contagious, and a good professor can make it fun to learn about anything. A great professor can make it fun to struggle and push against the limits of our abilities.

(Sorry, this is rather subjective...it is hard to quantify what makes a great teacher!)