How do I use colons and punctuation in this sentence?

Should I use a colon before a list? Which of the following is correct?

I’ll never forget that night when I sat staring at my laptop when it suddenly hit me: This is what I wanted to do. This is something that I would never get tired of: solving problems, finding patterns, and bringing order out of chaos.

I’ll never forget that night when I sat staring at my laptop when it suddenly hit me: This is what I wanted to do. This is something that I would never get tired of. Solving problems, finding patterns, bringing order out of chaos.

I’ll never forget that night when I sat staring at my laptop when it suddenly hit me: This is what I wanted to do. This is something that I would never get tired of. Solving problems. Finding patterns. Bringing order out of chaos.

If the first variation is the correct one, should I capitalize ‘solving’?

Also, should I capitalize the word after the first colon (‘this’)?

If I should make other changes, please suggest them.