The power of framing
Note: this is heavily inspired by William B. Irvine's thoughts and formulations
A big part of stoicism is controlling your thoughts, and how you think about things. Imagine getting tackled. If this happened on your daily morning run, it would most likely be a very traumatic experience.
Now, imagine the exact same tackle, but this time it occured during a game of rugby. This time you would probably not endure much mental trauma. You might even be happy, because you managed to pass the ball, and your team is up a try!
This illustrates just how important the framing of a situation is. Recall an experience with a postive frame, and you may laugh, but use a negative frame, and it can be unbearable. Good framing skills is a big part of having high quality thoughts, and as Marcus Aurelius once wrote:
"The happiness of your life depends upon the quality of your thoughts."
Here is another example for the gym-goers. After an intense workout, your sore muscles can produce an extremely strong sensation. Because you know the source of the sensation, and know it is the result of your workout, it is often heavily sought after. A sensation that under "normal" circumstances would be percived as unbearable pain, is a delight for many. It all comes down to your thoughts.