There's no doubt about it but we must not forget that the aptitude of the learner is also a critical factor in this matter. For instance, mathematics isn't everybody's cup of tea and for those who don't have the mental attributes to think through the problems that mathematics solve, it will be like a very difficult roller coaster ride. Hence, without the right aptitude, it's going to be very difficult to learn any subject even if it is taught skillfully. Many a time, it's all about understanding the student's aptitude, which good teachers are able to notice and make the necessary adjustments in their style.
Having said that, we must not forget that eventually, the onus of learning lies with the learner much more than it lies with the teacher, in line with the saying - 'you can take a donkey to the water but you can't make it drink'. However, if the learner has the right aptitude then it can be said that he has the hunger to learn. Hunger makes a man desperate and that's when he begins to exercise his mind to work around obstacles and get his hand on the object that will mitigate his hunger. In this context, another epic saying from ancient China comes to mind - 'when a man is hungry, don't give him a fish; teach him fishing'. Nothing articulates the principle of teaching better than this quote from the past.
Yet, there are endless stories of people making amazing turnarounds from near zero situations and in all these cases the efforts made by the learner to overcome his or her drawbacks has been significantly and equally important as the efforts made by his or her teacher. The role of a teacher in formulating the easiest methods to make the student understand is something that needs appreciation because only the teacher knows what s/he has to go through to get a clear idea of the student's psyche and where s/he is not able to cope with the tasks. I don't think any subject can be categorized as 'boring' because every subject has a value.