Originally Posted by dutchgirlDH

This is not correct.

Yes you can get a multiple entry visa even when your itinerary has one planned entry only. This is often based on previous travel and can even been granted when it had not been requested.

And yes, you can get a multiple entry multi year visa, up to 5 years in fact. Ask for that when you next apply and motivate why you need (and why they should grant you) one.

Both of these do depend a bit on the Schengen country where you apply though, some give multiple entry visas more easily than others.