cheekyzia
First, congratulations on this great score! I would have to say though that although this is a great success story, this is not the norm... I tried to study for a mere month and did not get anywhere near my final score of 700. After three months of intense study, I retook the GMAT a second time to achieve it. I think we should be careful of being overconfident... Obviously, if people like you get a GMAT Prep score of 760, then by all means go for the GMAT, you will definetly score high... but other mortals such as myself do need to keep in mind that the GMAT is a hard test and to get a good score a decent amount of smart and focussed studying is necessary to acheive good results.
You are absolutely right. I guess, I was at a good starting position (good math fundamentals from high school, studying towards a science degree in a prestigious university in the UK). What I really wanted to say, is that quite unlike most other tests, GMAT tests your logic and thinking skills, so studying could be a short process, provided you have good fundamentals.
BTW, I forgot to mention something crucial: while OG has an excellent Maths overview, it is extremely useful to know basic trigonometry - sin, cos, tan and their values at the most common angles (30, 45, 60), and the area formula (
https://www.clarku.edu/~djoyce/trig/area.html). It is possible to halve the time needed in some complicated geometry problems.