irritations and moods

I don’t know why very small things irritate and disturb my mind now. Is it a sign of old age, or is it normal, and I notice it only now?
I gave my car for service to a known garage where I personally know the management and many of the workers. While leaving the car there I had not bothered to remove from it a few things like a torch, a pair of sun glasses, some extra tools etc. But when the car was delivered to my house in the evening these things were missing. When I asked the mechanic who brought it he promised to check up at the garage and bring it back. Afterwards I was told over phone that they could not found. On contacting the management they said that none of the workers, who are all absolutely reliable, had seen it! But they had taken the car to some other place for washing. But there also none had noticed it. Thus these articles were lost. I could only be angry at myself for being careless in relying on their non-existent care and honesty.
Last month I gave an emergency lamp for repairs to an electronic shop. The owner technician was a friendly fellow known to me for several years. A pleasant smart chap. After a couple of days when I enquired he said that the battery needed replacement, and it would cost Rs 250/=. To avoid botheration of too many visits to the town I gave him the money and asked him to deliver it to my nephew’s office nearby. One week passed and nothing happened. I rang up. He said sorry, it was ready, but forgot to deliver it because of the busy festive rush. He will make arrangements to give it immediately. Five days again, and no news. He was out of station this time. His assistants in the shop had no idea where he had kept it! On his coming back he said that when he was checking it up before delivery, some sparks came out of it and it had become out of order. He would repair or replace it soon. Now it is more than a month. I have neither the lamp nor the money. But I have instead a nagging irritation of my foolishness in trusting an untrustworthy.
These incidents themselves are insignificant. But the irritation and uneasiness of blaming myself nags every now and then. Then I feel angry at myself. I know that I am being silly. But is the uneasy mood responsible for the nagging irritation, or the irritating memories create the mood?

Residues of actions and omission of essential actions accumulate in the mind. When my mood is depressing, they surface and pop up making me resentful about myself. Left-overs of unpleasant experiences linger on unless I am vigilant enough to notice them and understand them