beemer boy -
Wind doesn't push you to the side, it makes you and the bike lean into the wind.
Very strong wind gusts cause you to tilt dramatically, and many people steer away from it to straighten the bike up in a survival reaction. This is probably the source of the 'I changed two lanes' without even realizing why.
Don't panic when it happens. Also, be alert that trucks and vans can shelter you from the wind - when you pass them or they pass you and you're no longer sheltered, you can get hit with the gust.
Off-topic : This is different from the bow-wave of a truck, and different yet from the turbulence of following a truck. Stay a good distance away from trucks or pass them quickly.
One last note about crissing bridges: 'singing' bridges with expanded metal decks (the surface has holes for stuff to drop through) are negotiated best by squaring the bike to the line of travel (in case there's a curve before the bridge), and cross with only a light grip or fingertip pressure on the bars. Let the front of the bike shimmy and shake if it wants to. If you grip hard and force the front to stay put, you will transmit all those forces to the rest of the bike and the bike will shake. I've never had a bike I owned show any signs of trouble on these bridges.