I first saw this posted on the wall of my typing class in college back in the mid-90s. It's a warning to not be dependent upon your software to do your thinking for you.
Eye halve a spelling check her;
It came with my pea sea.
It plane lee marks four my revue
Miss steaks aye kin knot sea.
Eye ran this poem threw it
Your sure reel glad two no.
Its vary polished in it's weigh,
My checker tolled me sew.
A check her is a bless sing;
It freeze yew lodes of thyme.
It helps me right awl stiles two reed,
And aides me when aye rime.
Each frays come posed up on my screen
Eye trussed too bee a joule;
The checker pours o'er every word
To cheque sum spelling rule.
Bee fore wee rote with checkers
Hour spelling was inn deck line,
Butt now when wee dew have a laps,
Wee are knot maid too wine.
Butt now bee cause my spelling
Is checked with such grate flare,
Their are know faults with in my cite,
Of nun eye am a wear.
Now spelling does knot phase me,
It does knot bring a tier;
My pay purrs awl due glad den
With wrapped words fare as hear.
To rite with care is quite a feet
Of witch won should be proud;
And wee mussed dew da best wee can
Sew flaws are knot aloud.
That's why eye brake in two averse
Cuz eye dew want too please.
Sow glad eye yam that aye did bye
This soft wear four pea seas.