Then I reiterate my apologies! I have to say that I feel completely out of depth in pure maths stuff and I often feel dumb for all the questions that I keep asking myself! So I guess I feel insecure myself.
I am a bit surprised by your feelings because you are among the most knowledgeable and helpful persons to have helped me understand better diff. geometry!! There was another thread (which I can't seem to find anymore...are threads in the diff geometry forum regularly deleted? Are they archived somewhere?) in which you posted a few replies to my questions which were extremely clear and illuminating to me. You were explaining things in a very clear way, just at the level that I needed. I was really grateful for your input!