I completely agree..I mean from the psychological point of view the bond is the strongest with the mom/primary care giver, however it shouldn't be the only one...and a healthy kid is capable of bonding with both of their parents unless he/she is emotionally underdeveloped and I want to say "starved" of attention from one parent. As you said, a stranger truly.
"It was hard work keeping up my boundaries and keeping him away." THIS!!! So many people think it's "luck" when it's actually a "skill" you have to cultivate over time, train like a muscle.