The Happy Slow Thinker

Full many a time a thought has come
That had a bitter meaning in it.
And in the conversation's hum
I lost it ere I could begin it.
I've had it on my tongue to spring
Some poisoned quip that I thought clever;
Then something happened and the sting
Unuttered went, and died forever.
A lot of bitter thoughts I've had
To silence fellows and to flay 'em,
But next day always I've been glad
I wasn't quick enough to say 'em.