paint working time question

just wondering here... is it supposed to take FOREVER to paint a a vehicle well? im restoring a 73 chevy truck and im in the process of painting the cab right now... it seems like it takes at least 4 hours to sand between primer coats and im not looking forward to less grit paper in the next few coats... is this normal, as in is it supposed to take damn near forever do to a great looking paint job by yourself? it seems to me that every magazine that paints a car shows it as a simple one day process... its been a long one tho lol... any ideas or confirmations?