Is it just me or high pressure tires just weight a ton?

I had 40psi off road tires on my mountain bike but since I started commuting, I decided to buy a pair of 26x1.95 65psi slicks which are inflated to max pressure in order to reduce rolling resistance, but I feel that the less rolling resistance is compensated by the WAAAAAY heavier bike.

Am I doing something wrong?

Ricardo from Colombia