How to understand the sentence "regret for three years as a soldier, regret for a lifetime as a soldier"?

First of all, I have no intention of military service at present, and I won't have it in the future, because I know very well that my personality will be incompatible with the military camp, so I won't choose to be a soldier. On the topic of regret after being a soldier for three years, I will live after not being a soldier. Next, I will talk about my personal understanding of this sentence and put forward some different views? Let me talk about my understanding of this sentence first. The regret of being a soldier for three years is probably that the military camp has to endure three months of rigorous training for recruits, without running or stopping, no matter whether the weather is good or bad, every day is high-intensity training, and so on. It is definitely a cruel challenge for recruits. Many young people who have just joined the army are spoiled at home, which is a great test both physically and psychologically. In addition, in the army, individual interests are subordinate to collective interests. Since we have chosen a military camp, we must strictly abide by the discipline of the military camp. In the barracks, the freedom of soldiers is strictly controlled. Coupled with the boring work of standing guard all the year round, there will be a particularly big psychological gap for many people, and naturally there will be regrets about joining the army. Let's talk about not being a soldier and regretting it for a lifetime. Many veterans especially miss their days in the army. My father is a veteran, and he often mentions it himself. Moreover, life in the army also affected his later life. Probably many veterans, like my dad, like to listen to military songs, pay attention to current affairs and politics, and especially cherish the friendship between comrades. This is something that those of us who didn't join the army won't realize. Also, the army is a melting pot, and any sharp character will be smoothed away by you, which also creates the unique character of the soldiers. Although the military camp is good, it is not suitable for everyone. Everyone's life is different and everyone has the right to choose. Moreover, it is not that only joining the army can realize self-worth, but every post in society can. However, it is undeniable that the military profession is worthy of respect. Now is the annual recruitment season. I hope that friends who are interested in joining the army will sign up for the army. I like you. ?