Seeing the Beatitudes as "attitudes you should be" is a cute turn of phrase but misses the point of how Jesus begins his sermon. He begins by looking around the crowd of rejected, suffering, marginalized people, and affirms them as God's children, his special possession, and tells them that they have received God's blessing. When we answer the call to follow Jesus, he calls us to a way of life that is contrary to the way the world work. We must remember that the one who calls us is also the one who empowers us to live the way he calls us to live. It is out of the love of God and receiving his blessing that we are then able to put the Sermon on the Mount into practice.
If you are reading this right now, know this at the deepest core of your being: God loves you more than you can ever know and he wants to give his blessing to you.