Why think web accessibility is meant only for incapacitated people. Even you may be among them.
The word "Web Accessibility" sounds applicable only to the permanently disabled such as deaf, dumb and people with any other impairment. But that's not the case. It is applicable even to a user where he/she is facing a challenge when their PC mouse is not working. In such case, the user is depending on the keyboard itself. And can be treated as a disabled user too. The idea is to enable the users to use the web page in any condition.
There are many scenarios that can be considered under web accessing issues such as keyboard tab not allowing user to reach the option and enter key not allowing to open the page or make the functionality work. These scenarios too add to the list. And the list is exhaustive.
Web accessibility isn't as hard to understand as you might think.
It's a combination of common sense, empathy and understanding.
They're all traits that most humans share, so you've got what you need already!
Users read/understand websites in different ways, often making use of assistive technology (for example, screen readers, text-only browsers and keyboards).