Messing about with actual matrices never gave me the slightest grasp of linear algebra, and the fourier series formulae seemed completly pulled out of thin air, but as soon as I saw the expression of those concepts using abstract linear operators on general vector spaces, all the results and methods seemed obvious. I still feel really pleased when something that's true in my geometrical picture actually works when you stick numbers into matlab.
On the other hand, I first ran into group theory abstractly presented, and it meant nothing to me. I needed to play with lots of examples before I even cared about it, and before I came upon the cycle representation it was all just completely opaque.
They two seemed to be similar in content, introductory first-year maths, similarly presented, and both lecturers were clear and gave beautiful notes, and yet they spoke to me in very different ways. I'm still very happy with linear algebra and rather mystified by groups.
I think in my case the difference is that linear algebra is intrinsically geometrical, and I'm much better at visualizing pictures than at manipulating symbols, but given that one use of groups is to talk about physical symmetry, whereas linear algebra is all about vast tables of numbers, maybe that should be the other way round.
Anyone get the reverse feeling?
After reading Luke's interview with Scott Aaronson, I've decided to come back to an issue that's been bugging me.
Specifically, in the answer to Luke's question about object-level tactics, Scott says (under 3):
In a similar vein, there's the Halmos quote which has been heavily upvoted in the November Rationality Quotes:
Every time I see an opinion expressing a similar sentiment, I can't help but contrast it with the opinions and practices of two wildly successful (very) theoretical mathematicians:
Alexander Grothendieck
(from Allyn Jackson's account of Grothendieck's life).
Maxim Kontsevich
(from the IPMU interview).
Are they fooling themselves, or is there something to be learned? Perhaps it's possible to mention Gowers' Two Cultures in the answer.
P.S. First content post here, I would appreciate feedback.