Seeing two jokes fall flat on their face in the last two weeks illustrated the point perfectly.
The first was at work, when I overheard two of my colleagues talking about babysitting.
Being new, I imagined it would be a good time for some team building. After all humour can build bridges… when it is appropriate.
So one of my workmates is explaining that she is looking after one of her nephews for the weekend.
“He can be a handful,” she says. “But my boyfriend is with me so we can probably manage him together.”
Without even thinking I said: “One of you can hold him and the other can beat him!”
In the second incident the joke was on me. I was on the train to Wembley to see Arsenal v Chelsea in the FA Cup and the train was rammed.
At the next stop a giant of a Chelsea fan squeezes himself on… despite the fact that I am already being felt up (not by design!) by an old man.
I was reaching for my pockets to pull out my Mp3 player and he mistakenly thought I was trying to reach for his.
Without a trace of a mile on his face he says: “If you take anything out of my pocket I will remember your face, find you and kill you.”
The he bursts into gales of laughter.
All I could think of was the quickest way of changing my pants.