true story, I got my start programming by typing in two-line BASIC programs on the C64 display models in a Boots in South London. My family couldn't afford a computer at home.

10 PRINT "FART!"

20 GOTO 10

Not my finest code, I'll admit.

That was 40 years and a continent away.

I can't spot any obvious bugs in your code.

Although I would suggest adding a space after the exclamation point and a semi colon after the end of the string for a better screen filling UX.