Domhnall Gleeson was 20 in Six Shooter when he played the character 'Cashier'.
That was over 20 years ago in 2004.
This was his first recorded movie acting credit (although may not technically be his first actual acting role).
Today he is 41, and has starred in 38 movies in total, 37 of those since Six Shooter was released.
In Six Shooter, I think Domhnall Gleeson looks: