I can’t tell you how long I’ve been installing PseudoAnacron on every one of my OS X Macs.
Starting out with one that ships with every copy of Mac OS X, Disk Utility can do important tasks such as verifying any disk or partition, verifying and repairing disk permissions, and repairing any disk partition except for the one you’ve booted from, which is why we recommend having an emergency hard drive or thumb drive. There are a lot of good commercial utility programs available, but why spend money unless you need to? Here are a handful of very useful programs you might want to install on your Mac or your emergency thumb drive. All of those could mean it’s time to do some hard drive and system checks. Maybe you had to force-quit an application, or a program refuses to launch, or the spinning beachball of death won’t stop, forcing you to manually power down your Mac.
Macs tend to be pretty trouble-free, but sometimes things happen.