so i searched "haha" in my gmail and there are SO MANY results that google couldn't even tell me. they were just like "thousands. there are thousands of hahas in your gmail."
on the other hand, i've only used the word "mayonnaise" in my gmail/gchats twice, and once was in an email to myself titled "don’t let anyone see this poem. DO NOT SEND IT TO ANYONE."
good call, self!