Yes, this is exactly what I mean by "breaking programmer's expectations". Except maybe Modula, no language works like that at all. The parameters are in the parentheses, period. If you need to pass this, you do so in the declaration and in the invocation. If this is passed implicitly, you don't declare it in the parameters and you don't pass it at the call site.
Python is doing this totally weird stuff that sits in the middle and that makes no logical sense at all.
The fact that Python forces you to declare the "self" parameter is simply due to the fact that it's old, old, old. Nothing wrong with that, but post rationalizing it by saying it's okay to declare a method with 3 parameters but calling with just 2 is just silly.
Simply because it does not fit your expectations does not mean that it makes "no logical sense at all". As faulty beings, we often have expectations that really are quite far from logical.
GvR brings up the deeper reasons for explicit self at http://neopythonic.blogspot.com/2008/10/why-explicit-self-ha... .