"To 'unlock' a neurohelmet, the pilot transmitted a special, brief series of motions or entered some word or number command into the onboard computer. This code was secret and different for each individual pilot and his 'Mech, and prevented anyone else from simply climbing in and taking over the machine. Failure to transmit the proper sequence could result in damage to the helmet or the wearer." The Sword and the Dagger by Ardath Mayhar 1986.
Imagine no locks or keys needed on vehicles ....just moing into it an placing a helmet and with a certain number of commands or motions would allow you to drive ...the incorrect command or motion would get you nothing or possibly killed.
In MechWarrior Online, of course nothing feels close to this ...there may be a few people who say a prayer before dropping that the game wont crash or they are hoping to score a kill or a hit even. No risk involved at all.
The book gave me all new appreciation for the honor of piloting the mechs.