Is hair naturally thinner at the crown? and/ or looks thinner due to a colic or part where more line shines on the scalp?

Yes: If this is important to you, you can get minoxidil without prescription. The generic is cheaper than Rogaine and 2% is almost as effective as 5%. 5-alpha reductase inhibitors are prescription and are more effective. Some people use both. They are safe. Cheapest way is to get 5mg finasteride instead of 1mg Propecia. Use a pill cutter to cut 5mg into 4 pieces. It also reduces prostate problems.