If convicted and you serve no jail time, you can seek an expungement some time down the road. However, if you serve some time, future thefts - even if for a crayon - can be charged as a felony.
Though, your bragging may play out badly for you as it shows a lack of remorse. Additionally, it MAY be offered to show intent to enter the store the next day and commit theft and THAT, my friend, is second degree burglary - a felony.
Consult local counsel.
- Carl

