My parents have warned me not to spend a lot of money all at once, be careful when I'm out alone, and to have a good time. I'm not usually a partier or cause trouble so my parents never really had to warn me not to get into trouble, just to be careful when driving or whatnot. This advice is pretty valuable. It's good advice for someone going off on their own with enough warning not to do any stupid--to use their freedom wisely.
I have not really used this advice because apart from a week long band camp in the summer, I've never been completely on my own away from home. We had a very busy schedule during the band camp, and it was only for a week so I wasn't away for a long time. I have not been involved in any situation to which this advice was applicable, but it will be very applicable next year when I go to college several hours from home.
Laertes is grateful of the advice, although it delays his leaving for France. This advice caused Polonius to later send Ronaldo to spy on Laertes to make sure that Laertes followed his advice and is behaving respectably. Ophelia is probably a little resentful that her father basically told Laertes to do whatever he wants and he told her what to do and gave her little freedom.
