It happens when you get older.
Even though you're an atheist, perhaps you might read some of my posts to see if you get a feeling or message from them. Then maybe you'll get more of an idea what you're looking for. Wouldn't hurt to try. God does call people unto himself the way you describe.
I've been on a spiritual path for quite some time now, and I understand what you are trying to convey.
Strapitup · M
have you found what you're looking for?? or are you still looking??
@Strapitup: it's a continual quest, there's always more to learn and embrace. But what I've learned so far, has proved very valuable.