Do you often feel as if you’ve forgotten something? Do you lose your keys, wallet or your phone on a regular basis? Have you ever walked to the other end of the house and then been unable to remember why you headed that way in the first place? We all tend do those absurd things now and then. Most of the time, the consequences are not severe. We find our keys, wallet or phone in an obvious place and then just feel a bit stupid. We give it some thought and remember what we needed at the other end of the house. Occasionally, our forgetfulness can lead to bigger issues. Last fall, I scheduled professional proactive maintenance for my furnace prior to the start of Winter. I always make sure to call an HVAC contractor before the weather turns to ensure that my furnace is prepared for the heavy workload. I am rather proud of myself for taking these precautions, and I’m convinced that the service I provide my HVAC system pays off. However, at the tail end of this past winter, I noticed some issues with my furnace. It seemed to be working unusually hard, yet not producing much heat. I kept turning up the thermostat, yet the house felt chilly. I was aggravated by this, because I’d done everything I could to prevent diminished performance. Or at least, I was so sure of it at the time.Then I remembered something I do all on my own to take care of the furnace. I had neglected this task for the entirety of the winter. I never once replaced the air filter in my furnace!