Oy vey, where do I begin?
For starters, people have no idea what "keeping kosher" actually means.
Source: myrandomproblems
Explaining it takes forever and gets very complicated.
Source: bonappetit.com
In simple terms, you can't mix meat and dairy, you can't eat anything from a pig (yes, that includes bacon), and you can't eat any shellfish. There are some acceptable fish — any fish with both fins and scales. Eggs are OK and can be eaten with meat or dairy. Also, after eating meat or dairy, you have to wait a certain amount of time, depending on where your ancestors are from, before you can eat the other category. Any questions?
After that whole explanation, people assume that you're super-religious.
Source: danwymanbooks.com