I always press check the weapon when reholstering after it was out for awhile (like when I go into the jail and secure it), after loading it, before work, before operations (mandatory weapons check), and any other time I can think of. You never know.
Reminds me of two stories.
In training, after my second academy, we were being taken around our jurisdiction for a tour of some out-of-the way but notable places (one was the scene of on of the worst mass shootings in the country) and of some tunnels. Our FTOs lined up the newly minted officers and did a weapons check. I was the only one whose sidearm was actually loaded and ready to go. Two of the officers did not have loaded chambers, and two didn't even have magazines in their weapons. Nobody ever explained at the Academy that weapons should be "hot." Their were some butt-chewings and pushups.
The other one is the possibly true, possibly not story of a husband and wife duo who were both troopers and had the unfortunate habit of messing around with the other's sidearms. In one incident, husband loaded wife's weapon (thinking it was his) while she was taking a break from dry-firing. She returned to her practice and blasted their TV. Second incident was the opposite and worse. Husband on a traffic stop suddenly faced with an armed suspect pointing a weapon at him. First shot from the husband was a "click"," because his weapon didn't have aloaded chamber, apparently unloaded by the wife (turnabout is fair play). If I remember that one right, he did a good tap-rack-ready and center-punched his assailant, and came home from that one.
A couple months back, one of our guys asked me for a box of 9mm. Since we recently started issuing ammo for some backup and off-duty weapons (as opposed to making the guys buy it), I didn't think anything of it, since we mostly issue tens of thousands of rounds of .40 cal, since our issued duty weapons are SIG P229s. The next week, the guy came to me and said that all of his magazines were "rattling" badly, and he needed me to check them out. Hey, the weapons are starting to get old, and I have been replacing alot of magazine springs lately. I got into my trusty parts box, pulled out three new springs, and told him to unload his mags so that I can change the springs. He does so and spits out lots of gleaming 9mm rounds onto my desk (a P229 magazine will take .40, .357 SIG or 9mm without any problems). He had retired from another agency where they carried 9mms, and "9 millimeter" was slang for ANY pistol ammo (and this guy is a shooter and knew better). He had been walking around for several days with 9mm rounds in his .40 pistol. I just don't know how he chambered a round and holstered without the round falling out of the bore and onto the floor.
Point is ALWAYS, ALWAYS, ALWAYS check your weapon. Then check it again, and have someone else check it for good measure. Survival habits should become a matter of routine, where you would no sooner think about leaving the house without checking your weapon for readiness than you would breathing.