There are two related things going on. Firstly, the “typically” refers to normal, expected behaviour of most objects - that is, they are equal to themselves. But separately to that, many forms of comparison are actually defined as “is-or-equals”; for example, searching a list for an element uses this comparison logic. It’s not simply an optimization, and there is no way that something would be compliant without following this rule, but it’s almost never important because typically objects are equal to themselves. So you can mentally think about it as “find the first thing that’s equal to the thing you’re searching for”, with the caveat that it will find itself even if not equal.