Here is what your LE career would be like:
30% Responding to "routine" calls for service (nothing is really routine)
20% Trying to catch bad guys
5% Actually taking a bad guy to jail
5% Doing the plethora of paperwork just to book the bad guy
5% Going to Court
2% Laughs over a cup of coffee with your partners
2% Miscellaneous stuff
1% sheer terror
All things considered, I have had a good time. You need to have good common sense, thick skin, a good sense of humor, and calmness when Pooh hits the fan. LEO's, especially in busy areas see a LOT of horrible things. They also see a lot of funny things. Although there are some people out there who show their appreciation for the what we do, don't expect to see that appreciation, except on rare occasions. What keeps you going, is the fact you know you are doing the right thing and simply by doing your job, you are making the streets safe enough so people can sleep comfortably in their beds and so they can live their life. There will be let-downs and disappointments in your career, but also real highs.
Although most of your time will be taken doing a lot of "routine" stuff and dealing with thugs, there will be times when you are able to do something extraordinary that will have a positive impact on someone's life. It only takes ONE time to save a life to realize that if it weren't for you, that person would have died. For me, it was doing CPR on a drowned toddler who survived and is now living a normal life. When the call was being dispatched, other units were over 4 minutes away. I was 1 minute away. I did CPR for 2-3 minutes before paramedics arrived. That made my career. Scenarios like that are rare for LEO's.
One of the most important things; Realize that NOTHING is routine. I know I threw that word around a bit, but anything can happen and it sometimes will.