Riding on the sugar high of sth

Hans didn't know exactly what he wanted, bu the had tasted it. On the other hand, he did know what bored him to tears, and he was done with it. No more passing days as the living dead, no more dinners where his colleagues compared cars, riding on the sugar high of new BMW purchase until someone bought a more expensive Mercedes. It was over.

What does the phrase like "riding on the sugar high of ...." mean?

thanks in advance.