In my classes, the subject of gerunds and infinitives comes up. Students find this a confusing and frustrating subject. They accept that one can say "I like watching movies," or "I like to watch movies," but they will usually ask, "Which one should I use?" This question makes sense. I have seen most teachers answer this by saying "It doesn't matter, they both mean th same thing. Pick one that you like and use it."
I feel that there is a difference and that as native English speakers we intuitively know the difference and will choose the expression that conveys our meaning.
Sometimes, I feel that this choice is language mirroring. If someone asks you "What do you like doing," you will probably answer with the gerund, "I like watching." If they ask "What do you like to do," you will probably answer "I like to watch."
However, if you say to someone "Tell me about your interests," the person is free to answer, and some will give the gerund version and others will give the infinitive version.
My feeling is that infinitives express potential and gerunds express active things. If you say "I like to watch TV." it means that this is something you like but don't really do it that much. If you say "I like watching TV." it is probably something you do a lot. On the flip side, you could also interpret "I like watching TV." as you like the activity but it doesn't mean you do it. "I like mountain climbing," doesn't necessarily mean that I do it, have done it, or will do it.
What are your thoughts on this matter?