Nope. It is forgiving, believe me.
Let's face facts, shall we?
IE is broken, unsafe and full of unpatched bugs.
There are two dozen unpatched bugs., some of them months old.
There are regular, debilitating security problems, so much so that the US Department of Homeland Security recommends that people use something else.
It is a sucker for spyware, popups and malicious code.
It doesn't conform to standards and introduces new and broken "features" with every release.
Even if Firefox/Mozilla aren't perfect, anything is better than IE.