Honest question: What makes you say that? I've never completely understood why TeX is considered the best at handling mathematical notation. Personally, I've been very happy with the equation editor in Word 2010. I'll certainly acknowledge that there's likely better solutions than Word 2010, but before I invest substantial time learning something like TeX I'd like to understand exactly what it is I'm missing out on.
When people talk about TeX's mathematical typesetting abilities, they are often (from personal experience, as a math major currently in school) referring to having to typeset documents with many pages and upwards of 25% being math. It's much easier for me to type \int_0^\pi \sin (x) dx than it is for me to go click-click-click-click in Word. But besides that, when you're writing proofs, for example, and you have to keep referring to the same symbol, say sigma, over and over again, in LaTeX, you would simply write $\sigma$, but in Word, you would have to do Insert->Symbol or some nonsense. Several more seconds wasted, and that adds up when you have 100 occurrences of the character sigma in your document.
TeX has a learning curve, but it's not even actually that steep. Within 4 days of starting to use it I was already starting to grok it.