Eustress, or "good" stress, is the stuff that makes us feel good, get stronger, or otherwise invigorates our "souls." Lifting weights stresses our muscles and they grow stronger in response, and the exercise brings us a sense of wellness or peace; the other meaning of "eu" in Greek is "well."
Now much of the activity involved in fighting crime has a certain element of risk or "high sensation," such as driving fast, and it turns out we find that sensation a very powerful positive stressor. Living fast is a good euphemism for the young crimefighter's lifestyle, but sometimes it behooves us to evaluate ourselves and why we do the things we do.
For instance, no one wants to get divorced going into a marriage (I'm assuming), but many of us have been to the altar several times. My wife, the Sarge, and I talk about writing a marriage manual about how to ruin a marriage since we have each done it twice, giving us a collective wisdom of four failed marriages between us. High-risk, high-sensation folks just need to seek out new sensations, new "Eustress," to make them feel better. Knowing this about yourself could help you better understand your relationships.
Too much of any stress, good or bad, can be overdone, leading to emotional or physical problems. Lift too much and you'll be getting your right pectoral muscle reattached to your arm—a surgery that I, from personal experience, don't recommend. Driving fast may be fun, but the Memorial Wall is full of the names of our brothers and sisters who paid with their lives the price of admission for an "E" ticket ride to a crime.
You see, much of what we find fulfilling and exciting can be destructive to others and ourselves. Once we decide that the person or persons waiting at home just don't understand us, but that cute new K-9 handler will, we are seeking new stress and sensation that may feel positive at first but will be quite distressful later, and not only for us. Speeding through life is intense and exciting, but we need to find eustress that not only gives us a sense of joy, fulfillment, or wellness, but has less destructive side effects than many of the activities that we may be doing today.