Joyce uses the pun as a way of seeing the paradoxical exuberance of being through language.  James Joyce: Trivial and Quadrivial  (1953)

GV and TT p22 — Commentary 2: on “true strength” concludes as follows:

It thus comes into view that original “dialogue” as original ”dialogue” requires its own oblivion as the only way in which it can be the sort of radical plurality required by it as original and as “dialogue”.  Only so can it effect its own repetition in difference as its way of “creating the new”…

Because dialogue needs its oblivion in this way, it doesn’t lose itself through it, through its own absence, but gains itself. Thus it is said in the I Ching, and repeated by McLuhan on TT 22, that this genuine and total loss yet represents its “true strength“.

Something of this strange notion emerges in a conversation McLuhan had with John Lennon and Yoko Ono on December 20, 1969.¹

McLuhan: I think of this time that we live in as having come to the end of ‘steal’. You can use ‘steal’ in many senses, but when you become totally involved in each other, you can’t help but steal from each other. (…)
Ono: I prefer using the word emerge, or communication. Stealing, I mean, you can never steal anything. Nothing is going to be lost, you know.  It’s not like if you pour water in a cup, on this side [of the] cup — that this [other] side [of the cup] would be empty. When you pour [water into] it, both sides would be [equally] full, you know.
McLuhan: That’s right. The experience that is the result of the pouring is also fulfillment, is not emptying but filling. There’s a complementarity here.
Ono: That’s why I think, you know, this logical thinking made people start to be so fearful of giving because they feel that if you give, then you’re gonna lose. But it’s not that.
McLuhan: No.
Ono: Giving is getting too.² (127)³