After how many? Usage of AFTER

For example:

If there are 5 houses in the village and I passed 4 houses and now at 5th house I finally arrived to the destination. It took me how many houses to get there or after how many houses I finally found the right place I had to get to?

After 5 or after 4 houses?

Or another example to understand me:

If I am trying to find the right video or song and I watched already watched 4 videos and now I am on 5th video and that is the video I was looking for.

And someone asks me after how many videos did you find the video you were looking for? Should I say: AFTER 5 videos or AFTER 4 videos?

Or another example:

You have had 3 girlfriends in total. 2 before and now you have 3rd and she is the one you love the most. Would you say: I finally found the right one after 2 girls or 3 girls?

The question is should I count in the one which was considered the right one?

Since you're standing at the 5th house, you've crossed four houses before arriving at your destination. So you'd say I arrived here after 4 houses.

Comparing it to this situation. You've been given 7 bags. One of them contains a gold ball while the rest of them contains an ordinary metal ball each. Now, your job is to search the bags until you find the gold ball (Yay! Treasure hunt!). You search 5 bags, no luck. Now as soon as you put your hand into the 6th bag, you strike gold. You would then say – "Aha! After searching 5 bags with no luck, I finally found the bag with gold! I'm rich!".

This is because the word "after" is usually used when an action has been completed. For example – "After lunch, I went for a bath." The same logic can be applied to get answers to all your three queries.