Here are some randomly selected joke topics beginning with the letter 'C'
Change a light bulb
How many bankers does it take to change a light bulb?
Four. One to hold the bulb, and three to try and remember what the combination is.
Change
Madness takes its toll. Please have exact change.
Challenged
You're not old. You're chronologically challenged.
Change a light bulb
How many drummers does it take to change a light bulb?
None. They have a drum machine to do that that now.
Change a light bulb
How many British Rail staff does it take to change a light-bulb?
Two. One to change the bulb and one to apologize for the delay.
Chair
How do you make a hot dog stand?
Take away its chair.
Change a light bulb
How many psychiatrists does it take to change a light bulb?
How many do you think it takes?
Change
Boy: Can you change twenty pence for me?
Father: Yeah, that's no problem.
Boy: Good. Change it to fifty pence please.
Challenging
He finds knock-knock jokes challenging.