consider, v.i.

[Jonathan Lighter]

OED 5a ("to think deliberately, bethink oneself, reflect") needs a
tweak to cover the rather recent nuance exemplified in a current TV
commercial.

"A pretty good day - when you consider!"  (Viz., consider that you
narrowly avoided killing yourself.)

I'd add the whole phrase: "_when you consider_, colloq. when you
reflect on other possible outcomes."

Undoubtedly a truncation of "when you consider it."

It seems impossible to Google the intransitive phrase successfully:
exx. with complementary phrases seem unfilterable.

I'd be surprised if it's more than fifty or sixty years old, at least in print.

JL
--
"If the truth is half as bad as I think it is, you can't handle the truth."

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