I am...
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ISTP strengths
Optimistic and energetic. ISTP personalities tend to be cheerful, energetic individuals who always seem to have something to do. They rarely get stressed and prefer to go with the flow rather than plan their next steps.
Good at dealing with crisis situations. ISTPs do not mind taking risks (this can also be a weakness – see below) and can easily think on their feet, making snap decisions when necessary – crises do not really scare them.
Very creative and practical. ISTP personalities have a vivid imagination, especially when it comes to practical or mechanical matters. They find it easy to come up with novel ideas and do things in a way that no one has thought of before.
Relaxed. People with this personality type live in the present and often simply go with the flow, not worrying too much about the future. This is one of the main reasons why they rarely get anxious about something.
Know how to prioritize. Despite being quite unpredictable, ISTP personalities are very good at conserving their energy and releasing it only when necessary.
Both spontaneous and rational. ISTPs are able to combine spontaneity with logic, switching from one “mode†to another, depending on the situation. This makes them very flexible and versatile individuals.
ISTP weaknesses
Can be very stubborn. ISTPs are not too sensitive when it comes to conflicts and criticism, but they can become very blunt and irritated if someone tries to criticize their habits, lifestyle or ideas.
Private and reserved. Surprisingly, ISTPs can be very difficult to get to know as they keep most of their thoughts and ideas to themselves, especially when it comes to private or sensitive matters.
Get bored quickly. People with the ISTP personality type may find it difficult to remain focused on something for an extended amount of time, with their thoughts drifting off to more interesting things.
May be insensitive. ISTPs tend to be very practical and logical, and they may often inadvertently hurt other people’s feelings by failing to recognize the importance of emotions.
Enjoy taking risks. ISTP personalities are big risk takers and may often do that simply for the sake of having fun. For instance, they may escalate a conflict with a colleague just to see how they react.
Dislike commitments. ISTPs like to review their obligations on a daily basis instead of committing to something for a very long time. This can cause significant problems in their romantic relationships.
Source: http://www.16personalities.com/istp-strengths-and-weaknesses
^ That is very accurate.