Article reads like a well akchuallly to is your guitar in tune.

I probably haven't tuned my guitar to concert tuning for a long time.

I tried rocksmith and often tuned to that otherwise I just keep it in tune with itself and what approximately sounds right to me.

My fingers are too fat for any precision to matter too much. So long as it's in tune with itself intonation is vaguely right and the action is acceptable no one will notice my solo playing in the garage by myself is out of tune are the fifth harmonic.