Solomon had already demonstrated wisdom in discerning his brothers intentions, in dealing with his father’s enemies in a just way, and in making an alliance with Egypt.
He acknowledges, in spite of this, his inadequacy. He doesn’t limit himself to his own strength (wisdom), rather, he expresses a desire for all God has for him.
It’s natural to ask God for help in areas we are weak. But what if we made it a point, as Solomon did, to ask and rely on God in areas of strength too? What if God has far more for us in those areas, if only we would ask?