just to comment from the reverse of this, when i was 17-20 or so, i did a number of jobs - and was treated like crap...with no respect, rudeness and on one occasion outright scammed...
i was expected to grow up and get an adult job... so i turned up prepared to behave like and adult and expected to be treated as such...
instead i was treated like a skivvy or a child who they believed was too ignorant and wet behind the ears to notice the lack of respect or the rudeness
then theres the 'jolly old japes' played by the staff when they spot the newbie or rookie and play all the old tricks like sending them out for a bag of fallopian tubes and giving them all the utterly crap jobs, as well as sabotage, blame, and making them do their own work for them - and even personal tasks - to save them the bother...
i was young but i wasnt stupid, i knew what they were doing and i see it as a form of passive bullying...its often cruel, abusive and mean, rather than a jolly good jape, and leaves people feeling embarassed, frustrated and angry ...
young people know they may be treated this way ...
i look younger than i am and even now i am treated like i am 'just a kid' and now i am old enough to spot it a mile off and its horribly patronising and conndescending and downright offensive...and i find myslef having to instigate conversations designed to make my real age know... and it works...attitudes change instantly...
and i have never and would never do those sorts of jobs again...