Solomon had unique resources for investigating life. He was the king of Israel (v. 12), and he possessed superlative wisdom (v. 13; cf. v. 16; 1 Kings 4:26-34). He says he made a comprehensive study of all kinds of human activities (v. 14). He observed that they were all a "grievous task"(v. 13; cf. 4:8; 5:14), namely, meaningless.
"Striving [chasing] after wind"(v. 14) graphically pictures the futility Solomon sought to communicate (cf. 2:11, 17, 26; 4:4, 6; 6:9). This phrase occurs frequently in 1:12-6:9 and is a structural marker that indicates the end of a subsection of Solomon's thought (cf. 1:17; 2:11, 17, 26; 4:4, 6, 16; 6:9).
Solomon was saying that there is no type of effort or action that can produce something ultimately permanent and therefore satisfying. There is nothing people can do that will yield this, no type of work or activity.
