I find the Chemistry Cat/Science Cat Meme frequently has me laughing out loud. You can find these all over the internet, I just found a link for you that has a gallery of some of them collected. I like nerdy humour.
Unlike other types of jokes, I can usually understand science jokes and puns. I am that person you never want to tell jokes to because I never get them and you end up spending 10 more minutes trying to explain why it was supposed to be funny. Stick to nerdy humour, bathroom humour and the occasional naughty jokes and we’ll have no problems.
I found one that reminds me of one of my Dad’s coffee cups which has pretty a similar fission joke on it: