Er, um, I get the impression Professor Einstein is getting exasperated with the denseness of the pupils (well, this one, anyway).
The whole conundrum has too many slippery variables, it seems to me. We always feel like we're in the present, but in reality, yesterday is at best a stale today. (Bet you're rollllling your eyes, now, eh? Sigh, well, I'm not a philosopher; I'm more of a poet...Philosophy always gets me chasing my tail.) And tomorrow is only an embryonic today. So, they're both not really the "present."
(But then again, it sounds like nothing but semantics...ACK! Reminiscent of a mirror that reflects in a mirror that reflects in a mirror.....

)
[LATER] I just reread that and realized, it's nothing but Jabberwocky. Drivel. LOL! Methinx I need to hit the hay, or at least, not try to tackle hairy topix this late at nite.
Pollygeez for the hot air.