Your train of thought is always there, it just waits for you to step aboard. After all, you're the engineer and the conductor. You're the pilot of the plane, captain of the ship and the leader of the pack. It's all in your mind. You choose which turn to make, which stop to take, when you should refuel and many other decisions. Despite the reposibilty, it's much easier than you may believe and the end result is worth it.
Experiences may change the course that you have orginally planned before. Maybe you planned to be with someone for years and it only lasted a few months, it causes you to rethink, replan and set a new path on which you may find someone new to accompany you on your travels. That someone may also help in your working or school life, everyone needs that support, pride won't always help. As in some cases, pride goes before the fall. Then other cases surface where pride is exactly what you need. That self motivation, fueled by ambition and the willingness to be successful. That's what some of us need to direct our train of thought across the right tracks.
The way you view yourself is also important. One can't expect to think low of themself and look for greatness, there's a difference between being humble and being "walk over". Humble yourself, you'd be respected for it but never let yourself be walked over. That's giving someone else the ability to block or hinder your path to becoming a better person and improving your self image that will in return help with your thoughts as you continue traveling and advancing into the unknown future.
Prepare yourself, some things are not as easy as the seem. From your view you may only be seeing the tip of the iceberg. The tracks maybe frozen as you travel through cold hearted times. Look for the friction you need, negativity will never be benifical but positivity will automatically brighten days and give you the needed friction to keep your train of thought on track. No matter the location, the surroundings, the weather, the feelings you have, keep your train of thought heading in the right direction. One of positivity.
So after it's all said and done, ask yourself.. Where is my train of thought heading?