I always had the tendency to think about all the negative scenarios, their consequences and how to get out of them
. But thinking positive is actually better, puts me in a better mood and lets me make good situations even better
And yeah, as it was said, if he asked you out he already likes you. And you like him. Now you guys will go pn a date. Cliched, but this time actually useful, be yourself. Because that's what attracted you to him in the first place, as you said (and yeah, quirky girls can be very attractive), so just have fun, as you should in a date, and enjoy your time with him. Soon enough, things will start flowing, self-consciousness will go away, and good conversations happen around that time.
Good luck!
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To build may have to be the slow and laborious task of years. To destroy can be the thoughtless act of a single day. - Winston Churchill