Same here, Molly! Mine is 4 years old without anti virus. I do have malware remover (MalwareBytes) because it does get malware, spyware, adware, whateverware. They're easy to spot and MalwareBytes doesn't take up that much storage and memory when it's running. I also use Dr. Cleaner to clear system files that accumulate and to monitor my RAM usage because of the programs I'm running. But other than that, it runs smoothly and no problem without these added stuff (although it's better to have, at least a browser adblocker)