Hitting Shuffle over and over brings back the same order of songs

[Caplonk]

When i like to hear random musik of my library, i usually hit the "shuffle"-button until the order of the next ~15 songs sound interesting to me. But sadly the same songs hit the top of the list over and over again. That's not what i was expecting. Is there a way to change this? Couldn't you just implement a truly shuffling algorithm or is there some thought behind that i missed?