No need to be sorry, the matter is a bit complex and not really well explained in an accessible language, the usual given reference is this:
http://forum.mikrotik.com/t/advanced-routing-failover-without-scripting/136599/1
but check this thread, hopefully it will help you:
http://forum.mikrotik.com/t/primary-gateway-with-static-ip-address-not-activating/183380/1
starting from here:
http://forum.mikrotik.com/t/primary-gateway-with-static-ip-address-not-activating/183380/1
AND links given there.