A desire is a transitory thought. Lust is taking that transitory desire and allowing it to control your thoughts. Huge difference. Going through puberty I started having sexual thoughts about girls in my classes. The harder I fought the harder they came. I then quit fighting them and let them go to my mental trash bin. Doing so they just flicked through my mind and were gone.
Are you trying to say as a man you have never dealt with this? If your answer is no I believe you to not be telling the truth.
When I made a commitment to Christ at a young age, I was in earnest about it. I set out to live a pure and holy life for God, in effect obeying His laws(though at my tender age I did not rationalise it that way) The first real difference I noticed was, I became conscious of my shortcomings/sin before God in a very real and profound way. I suddenly knew I could not continue to live as I had previously if I wanted to be a Christian, for Christians cannot expect to live a life of sin. The consciousness of sin was not due to having firstly read the bible, but because the law had been placed in my most inward parts and there was no hiding from it.
I didn’t love others as I should(I was only young) I used to get angry(as kids, and adults do. I told some fibs, and a lot more. And I always felt much guilt because of it. But it was when I reached puberty the problems magnified, because along came impure thoughts. I used to panic every time they came, for I did not want to go to hell due to my impurities, the more I feared them the worse they got. I became a slave to masturbation and was full of all manner of concupiscence.
I had felt alive without the law once, but when the commandments came, sin consciousness sprang to life and I felt condemned. The commandments that I believed were ordained to life if I obeyed them, instead brought death/condemnation for I could not keep them. I gave up with church in the end, for I would be a hypocrite to remain. On the outside I could act real holy but on the inside I was fully corrupted.
A few years later I read a book. In it was a chapter on Paul’s message of grace. I dared to believe I could be a Christian after all, for it did not hinge on my personal goodness but faith in Christ, that was my righteousness before God. But what of the sin? I was still full of all manner of concupiscence and a slave to masturbation, I just left it in God’s hands and trusted I was saved for Christ died for me. The next three days were real hard. A voice constantly told me in my head I could not be a chrisxtian and do what I was doing/masturbating. I was just being a hypocrite. It was so hard to ignore that voice after my earlier years, but I did, I trusted I was saved because Jesus died for me. On the fourth day, that sin I had been a slave to for many years stopped. As Paul wrote:
For sin shall no longer be your master, for you are not under law but under grace Rom6:14
BTW
When I first reached puberty, obviously lust was not fully grown in me. But I knew desiring women was sinfull.