And I guess that I enjoy more the experience of riding them, testing them, tuning and building them than the act of collecting them.
Same here. I obsess over every stage of finding, buying, cleaning, repairing, purchasing parts for, and adjusting every bike I own. But once all of that work is completed and finalized, I lose all interest in the bike, and find some excuse, any excuse ("frame is too small", "too much flex / too heavy" "I don't like the paint job" "I'm tired of frames made of that material", etc.) to take the parts off and put 'em all on a different frame and start the process all over again.
Makes no sense at all, not even to me, but I'm uncontrollably driven to do it by some strange force that defies explanation. Fortunately I have found others here who also have this disease, so I feel at ease knowing that at least I'm not alone.