"Normal human behavior" is described in the Bible as "sinful behavior". Even when it does not appear that any action or speech is sinful, or 'weak', the Bible states that even our righteous acts are as filthy rags in God's sight (Isaiah 64:6). Paul quotes from that section in Isaiah, applying it to his day. Romans 3:9 starts:
"We have already made the charge that Jews and Gentiles alike are all
under sin. As it is written, 'There is no-one righteous, not even
one...'(and more from Isaiah chapter 64.) N.I.V.
The best way to get a satisfactory answer to the question is to look at the problem from God's point of view, as he is the holy, righteous judge. But if sinful people judge themselves according to their idea of what sin is (or isn't), they might easily salve their consciences and excuse themselves: especially if the object of the exercise is to "not feel guilty"!
A problem, though, is how judgmental and legalistic many people are on the topic of identifying "works of the flesh". They take the clear, straight-forward warning of Paul (which you quoted) and declare all sorts of things as being 'unclean' or 'fleshly'. Prohibitions start to abound. Punishments are threatened, and poor souls end up so fixated on what they should, or should not do, they have a massive guilt complex - all because of what other people say or expect.
Paul is quite clear, and if taken in context, from verse 1, it's obvious he is contrasting how those without the indwelling Holy Spirit struggle and how they live, whereas Christians who have the Holy Spirit live in his freedom, and are alert not to let themselves be caught in a yoke of sinful slavery again. Now, if a person has never yet come to new, spiritual birth by the Holy Spirit, they have never been set free from the burden of their sins. Their consciences will either keep condemning them, or become hardened, seared as with a branding iron. There is no "solution for recovery". The Bible says the sinful human nature has to be "crucified" - put to death. It's not supposed to "recover". It's supposed to be destroyed utterly! And only a miracle of grace will do that.
"Those who belong to Christ Jesus have crucified the sinful nature
with its passions and desires. Since we live by the Spirit, let us
keep in step with the Spirit." Galatians 5:24-25, N.I.V.
Us sinners have to admit to God that his judgment of us is entirely true and that we deserve his wrath. We have to start seeing the enormity of our sin, from his point of view, which should get us on our knees in confession and repentance. When we waken up to the fact that we are lost in our sin, we cry out to God for mercy and forgiveness. We believe that Jesus died to deal with our sin, and that only faith in what he did to deliver us into new, spiritual life will destroy our sinful nature. Then we will "belong to Christ". Then liberation will come. The sinful nature will no long control us. We will have a new master, being willing slaves of Christ. And the Holy Spirit will continue his work in us for the rest of our lives. As we grow in grace, taught of the Spirit, the flesh will have less and less of an appeal to us. Spiritual things will become our priority.