Why do you need to shift it into forward? Why not leave it in neutral? Also do you live near a railroad? sounds like you got a lot of trains coming by. lol
I place the gear in forward for 2 reasons. The gear has a natural tendency to go into forward. Does not take much to knock it into forward from neutral. 2nd. When reinstalling sometimes you will need to turn the shaft just a little to get the shaft spline aligned to the engine. With the lower unit in forward you just turn the prop to get the shaft aligned with the engine.