Want to be a rapper does it matter what i rap about?

im good at just making up things to rap about but i want it to be good and i dont want it to come off as im fake, been interested in rapping all my life just really started taking it serious.. like can i rap about me havin money even tho i dont really have much.. like rick ross and lil wayne rap about being ex drug dealers and gangstas even though they both neva lived that lifestyle lil wayne been rapping since 8 and rick ross was a police officer they got exposed and still they are known as two of the top rappers in the game im not hating they are two of my favorite rappers but i dont c how they are still getting respect if they are being fake and lying.. i guess people dont care and it's just about the music and entertainment