This phrase is not exactly slang, but a traditional saying or proverb. It roughly translates to 'he who only laughs at his own mischief remembers it'. It suggests that a person who enjoys their own tricks or wrongdoings is likely to recall them due to the pleasure they derived.
Examples
- Spanish: Juan siempre se está riendo de las travesuras que hace. Como dice el dicho: 'El que solo se rie de sus picardias se acuerda'.
- English: Juan is always laughing at the pranks he pulls. As the saying goes: 'he who only laughs at his own mischief remembers it'.