The reason why various thoughts feel a certain way is due to the underlying structure of reality being vibrational in nature. As you think a thought, you are really only experiencing a vibration of a certain frequency. The thought being considered will then alter your personal vibration which in turn will result in an alteration of your physical location within spacetime. The location within spacetime into which a thought moves you is always of a greater likeness to the thought being considered than the previous location within spacetime at which you resided prior to thinking it. Ergo, every thought you think moves you into an area of spacetime that better matches the nature of the thought being considered.
Therefore, the way a thought makes you feel indicates the nature of the future reality in which you will exist as a result of thinking that thought. Thus, thoughts that make you feel good are really only vibrations of a desirable quality that will ultimately alter your vibration to better match their nature which will then alter the nature of your reality to also better match their nature. In other words, thoughts that make you feel good make you feel that way, because they are making your reality more desirable in the thinking of them. The more desirable are the thoughts you think, the more desirable is the vibration from which they are composed and thus the more desirable will be the future reality into which such thoughts will take you. By understanding the mechanics of this phenomenon, you may now easily understand precisely why various topics make you feel a certain way and you can now also direct your attention towards the most desirable topics possible so that you may create a more desirable future reality for yourself.
Being that your emotions represent the vibrations to which you are being exposed in any given moment, you can thus use your emotional state as an indication of the desirability of the future reality into which you are presently moving. The future reality being created in any given moment will produce an emotion like that which is being produced by your present thought since the future reality will be composed of a vibration that is of a greater likeness to the vibration to which you are presently being exposed. For instance, the happier does a thought make you, the happier will the future reality then being created make you. Strong emotions indicate you are being exposed to a vibration that differs drastically in nature from the present state of your reality. Ergo, the stronger are the emotions experienced in the thinking of a thought, the greater is the degree to which that particular thought will change the nature of your reality. You can use this information to make rapid changes in your life by directing your focus towards thoughts that produce the strongest and most desirable emotions within you so that you may create a reality of a matching nature.