Given the amount of cricket most of us play, it does definitely take a season for us to open a bat.

If we all count number of balls we hit on the bat every week (a guess), that helps. For example, if I go to team nets, batting is for 15 minutes and in those 15 minutes, you get to face 36-42 balls (6-7 overs) out of which half are the ones which are either bouncers, wides, or something which you leave. The remaining half which is 18-21 which is which you hit the middle or off centre. So, in 18-21 balls, you can't really open a bat.

You need to hit at least 500 balls in the middle to have bat opened up.