CE560 XLS Captain reported inadvertently moving the throttles to the cutoff position in-flight. Reporter also noted they did not inform anyone about the incident and post flight action of actuating the cutoff triggers multiple times.

Narrative

After receiving a crew member's report request; I reviewed my logbook. I cannot remember all the particular information about the flight or what happened that week. Based on the date; I would have started my tour in recurrent at ZZZ; then sent home for the hurricane; and finished that tour on the line. I vividly remember being the pilot flying at altitude; pulling the throttles to idle; and the left engine going past the gate into cutoff. I instantly returned it forward of the gate and turned on the ignition switches. There was no loss of power or any irregular engine indications. We did not inform anyone at the time. It was my fault how I was cupping the throttles. After the flight; I actuated the cutoff triggers multiple times; everything being normal. Referring to my logbook; we did another flight right after this one. I should have set the brake in ZZZ; called the Chief Pilot; and informed them of what I had done. I can only speculate and make excuses for why I made that bad decision.I still can't remember any conversations with the SIC. Referencing my logbook; I have been to ZZZ a couple of times; and this was the only time as PIC and pilot flying. I remember landing runway XX; aggressive braking; and turning off at [taxiway] 1 or a 180 on the runway. I know we did not taxi on the east side of the runway because I remember the long line of airliners on that side and talking to the owners about the long line on the ground afterwards. I have pieced the engine incident and my last time in ZZZ together; but not as one complete flight yet.Suggestions: I need to slow down and focus on one flight at a time and not worry about the whole day.