Old or Senior?

Consumption of my stock in my hobby is increasing these days because of accidents caused by just only trifle mistakes, and these disasters could be avoided if I should pay much more attention on the preliminary investigations based on the basic principles.
I feel that my thought is not so cheerful and intelligent as before that I was working in business as a First-line Fighter.
I have been released from the time restriction, no obligation to be forced to do quickly, no external stimulation to make haste. I'm going with "Hung loose" too much? I'm far from tightening and concentration utmost.
Are they some typically specific phenomenon observed in a Geriatric?
Though I'm an available person, do I recognize myself to be an aged senior citizen?