See also:3. The Use of si to Express Dative: An Experiencer
Czech si is very active in the expression of Benefit. In a sense, si can be used as a sort of barometer to determine what behaviors can be considered self-indulgent by the Czechs. Thus there are interesting distinctions between the uses of verbs with and without si, such as: hrát ‘play’ vs. hrát si ‘play for fun’, házet ‘throw’ vs. házet si ‘throw for fun’, kopat ‘kick’ vs. kopat si ‘kick for fun’, etc.
REFLEXIVE SE/SI - Complex phenomena
4 In this function, si is (...) somewhat superflous, and can be deleted without a loss of meaning or grammaticality: jít si na výlet - to go for a trip, mazat si to domů - to hurry home, počkat si na někoho - to have to wait for somebody, už si odpracoval dvě hodiny - he has already worked off two hours. (source)
I beg to differ on the topic of the inexistence of the phenomenon in Russian, which does exist, even though its usage is on a much lesser scale. But I will not, as this is a Czech forum
I would love to hear about the state of affairs in the rest of the Slavic languages (I mean it, so feel free to PM me). To keep it short, my argument is that говорить себе, играть себе,Perhaps I wasn't specific enough: I meant Russian doesn't have the "dative of experience" usage reflected in the short-form reflexive pronoun "si" attached to the verb. There's no parallel говорить с(еб)е , играть с(еб)е , подождать с(еб)е usage in Russian.