Why is Word acting like a bitch?

For some reason, the spell check refuses to recognise words like conflict and influence. Do you think it's just being cheeky? Like it knows that I'm up at 2 a.m. with a blue nose and frozen fingers and 5000 words to write in a few hours, and just really wants to pull my leg.

Ha ha. Good one.

Get your shit together, Word. I don't have the brain power to spell for myself!