Hi all, I have been in the physicsforum for a while already. I am a graduate student in mechanical engineering now, studying fluid mechanics. I did my undergraduate in mechanical engineering as well. The kind of fluid mechanics I do is a bit mathematics and physics oriented. The best way to describe it is really fluid physics. With an undergraduate background in engineering, I really feel I know so little about physics and mathematics. I have been comparing myself to other physics students doing similar things. The physical intuition and mathematical maturity they have are way beyond me. I actually did very well in my engineering classes, and I still do very great in graduate classes now. But the gap between me and other physics students in terms of research ability is so huge. I feel like I lack a rigorous training even in mechanics. Hamiltonian? Lagrangian? I did not really learn these things in engineering classes. But these concepts seem to be really useful in theoretical fluid mechanics. I really want to fill in the gap. I am wondering if anyone here have the same situations here? If you mange to fill in the gap, how did you do it? Any sharing?