Damn I've forgotten that word again!

You sit and wonder and try to think
But the word has gone out of your head with a plink
It's beyond annoying, the worst thing ever
It really is a great endeavour
Clearing your brain does not help, you find
'What the hell is that word!' just returns to your mind
You ask someone else, but of course they won't know
And so for ages you're annoyed and full of woe
Dictionaries and thesaurus's don't help a bit
You've suddenly remembered! How could you forget! You twit!