@Walter_vi_Britannia
Is everybody here forgetting about the term "inheritance"?
First, we don't know what he inherited (except a house and some money).
Second, he likely lost a huge part of his inheritance due to
inheritance tax.
Third, you forget that he's just a kid without income.
He's probably still got many years before he's legally allowed to work, to say nothing of the years he still needs until he's finished with all his studies.
Until then, he needs money for food, education, health care, and to pay taxes among others. If he spends his money blindly, he'll run out.