There's no such thing as a free lunch
(South Park, PA)
My mom was a nightclub dancer in the '50s and absolutely beautiful. She was used to getting gifts and attention from everyone for most of her life. This phrase is something she learned the hard way and always told me because the fact is that everything in life has a price. We all pay something someday.
You should say it to yourself when someone is offering you something that appears to have 'no strings attached' because there are - believe me.