It’s simply a play of words - high (pronounced as 'hai') - means 'Armenian' in their native language, apparently.
"So, we are walking in the streets of Amsterdam, enjoying one of our greatest trips so far, and suddenly we see a guy - with a typical Armenian appearance. Anush says: "Hay a hastat (translated as 'He is definitely 'Armenian')!" and I'm like 'hay a!'. Imagine our faces when the guy turns to us and says: "Girls, it's natural to be high in Amsterdam, why are you so happy about that?" explains Inga.
They decided explanation was useless and continued their trip to a museum.