Why some students think that programming is difficult and hard to learn, how I convince my students that programming is not difficult as they think? Some students think that programming courses are tough and hard. I personally know some teachers who say to their students that programming is not their cup of tea. How much percent this thing is true that learning programming is tough. According to me if people interested in this then nothing is difficult for them. How can I convince my students that programming is not as difficult as they think?
Careful! That's a pretty aggressive statement, and is liable to make folks who really do have trouble feel pretty bad about themselves.

You may want to take a look at this question. Whether you believe the answer to ultimately be yes or no, you will find that even the most adamantly "no" teachers admit to some number of students who have enormous difficulties 

Interest is highly important, of course, but how your brain is wired matters a great deal as well. Don't discount real difficulties that people face. That's the kind of thing that causes people to beat themselves up mentally, when they're alone with their own thoughts.  Interest is important, but may not be sufficient, and dismissing the problems others face can be unkind.