Quoted from mrniceguy

...the traditional rites of passage of pinball ownership.  To enlighten, or remind you, here are the steps :

1.  Initial curiosity, followed eventually by trepidatious purchase of a single pin.

2.  Promise to wife that 1 machine is all you are ever getting.

3.  Realization that owning 1 pin is ridiculous.  You either own many pins or none at all.  You opt for the former.

4.  Begin process of justifying to wife why having 1 pin is silly.  She capitulates. You buy between 2 and 5 more pins.

5.  An interim period lasting between 2 and 6 months where you are almost satisfied with owning half-dozen B or C-list titles.

6.  Through visitation of the homes of other collectors, you realize you will never be happy with your stagnant and finite collection of tattered and boring pins.

7.  The process of justifying the purchase of more pins by employing the "logic" that they are actually investments and you will be able to flip them eventually.

8.  The search for areas of your basement that are being under-utilized.  Statement such as "She can really do the laundry in the garage, right?" or "Do my kids    
     really need that much square footage in order to play happily?" are often posed during this phase.

9.  The epiphany that no matter what you do, your wife will think you are an idiot.  In fact she already does.  Do you really think she will respect you more if you
     have 5 machines in the basement as opposed to 10, 12 or 20 ?  You become enlightened.  You have nothing to lose.

10.  Nirvana :   You have been set free. Your mind and body are awash in the pure bliss of the knowledge that an infinite supply of pins await your purchase.
      No longer shall you be afraid, oppressed or remorseful.  You are a man. You are a hunter. A collector, and you answer to no one.

Quoted from websherpa

Every good top ten list should have a

#11 Get bored or go broke... then eventually find new expensive/obsessive interest and go back to step 1 (substitute "interest" for "pin")  

Quoted from Monkeybug

"wondering to yourself how you ended up with a house full of machines and the madness that was involved along the way."