why so much pda?

I am so over constant public display of affection occurring left right and centre everywhere! I'm not overly cynical (most days) but seriously in the past few days whether it's the hormone-crazed year 8's in the locker room or the couple walking home from the train station or the early twenties on the beach; everywhere people are just hard out making out in front of the whole world to see! I mean a kiss on the forehead, a hug, a peck on the lips/cheek that is cute, that is appropriate but when you see them push each other up against a fence it crosses that unspoken boundary of general lameness/ridiculousness (whoop for vocab!) It's sad because all I can think when you see these couples who are clearly still happily within the few month bubble all I can think is a few weeks, months or even years down the track they're going to look back on those moments and either think "what the fuck was I thinking?" or "what the fuck went wrong?". Either way it isn't positive. Anywho perhaps I am just being extremely harsh and cynical and perhaps I should too join the pda band wagon and get meself a good ol' public hook up (sarcasm intended).