As we come to Psalm 122 the psalmist has taken two steps up the staircase of spiritual victory, and be sure it is an uphill climb! In Psalm 120 he has honestly acknowledged his condition, and inability to help himself. Secondly, in Psalm 121 he has changed his look to an upward look, but he still has a ways to go before his journey is complete.
In Psalm 122 he listened to, and joined God's people who were going into the house of the Lord. He did what he knew he needed to do, and that was to begin journeying towards the Lord's house. He didn't get where he wanted, and needed to be immediately, but he is now moving in the right direction. Once he starts for God house some like minded folks cross his path. They are headed in the same direction, and going to the same place as he. In fact, they encourage him to continue on in with them!
Are you living a defeated Christian life? If so, why don't you learn from the psalmist, and yoke up with those who are spiritually going in the direction your going, and interested in attending the house of God, and living for Him. If you will they will help and encourage you along the way, and like David at the first of this psalm you can say "I am glad". Stay with God's people long enough, and you will find yourself positioned and living victoriously.