Hahaha. I dunno . . . maybe it's like one of those optical illusions where one either sees the old crone or the lovely lady. For the life of me, I cannot visualize the meaning you are assigning to that statement.

If no matter where one estimates "it" to be, the actual value will always be higher, then it seems to me that one can, and in fact must and always shall, underestimate "it." In that case, however, one cannot overestimate.

Then again, maybe it's a trope that has slipped into the language like the exceedingly common use of "I could care less" to mean "I could not care less." Or the dialectical use of "I don't care to" to mean "I'd be happy to."

Hopefully by now you can see that I'm having a bit of fun. Hopefully you could care less. :)

Herring405