When occurring as object of a preposition like this, both my colleagues and me and my colleagues and I would be found in the formal English of standard speakers. Of course, there are always people who'd like to try and rationalise the facts of the language into what they feel would be a more sensible way of doing things. But you can no more rationalise a language into common sense that you can rationalise your body into a more rational shape. If trying to make English into a different, more rational language, we could argue that because the first person pronoun in the co-ordination would appear in the accusative case if it appeared on its own as the object of a transitive preposition, it should appear in the accusative case when in a coordination:
- a course for me
- *a course for I (ungrammatical)
However, this ignores the fact that this pronoun is not the object of the preposition in the Original Example. The grammatical object of the preposition is a coordination of noun phrases.
Huddleston & Pullum say the following about non-subject co-ordinations with I as the second coordinate:
Because these coordinate nominatives are perceived to be associated with the avoidance of stigmatised accusatives in subject coordinations, they are often described as hypercorrections. This is to imply that they are 'incorrect', not established forms in the standard language. Construction [32i] with I as final coordinate is, however, is so common in speech and used by so broad a range of speakers that it has to be recognised as a variety of Standard English, and we will reserve the term hypercorrection for examples like [23ii] and [24].
An example sentence from [23i] is:
It would be an opportunity for you and I to spend some time together.
Regarding the CAE exam, it highly doubtful that the case of the pronoun in question is going to make any difference to the grade here. What is required is natural language of the appropriate style. Both me and I will suffice for this purpose. In terms of helping the student, I would tend to err on the side of range rather than absolute accuracy in any case if you are after one of those elusive higher grades.
I was going along the street, and suddenly something happened, and I
was like WTF!
It could mean, "I was going along the street, and suddenly something happened, and I said WTF!"
However, usually the person did not say those precise words. "I was like ..." is more a way of relating a reaction or even an emotion.
So it could mean, "I was going along the street, and suddenly something happened, and I thought/felt WTF!"
He told me something, and I was like dude really?
This translates as, "He told me something, and my reaction was 'dude really?'
Sometimes it could refer to verbatim speech but usually if someone wants to relay the exact words they spoke, it will go as follows:
'He told me something, and I actually said to him, "Dude really?"'
This emphasises a precise memory of what was said.
The expression is very informal and would not be expected in a business meeting or similar.
Best Answer
Both “in a nutshell” and “hot topic” are phrases more informal than one expects to find anywhere in a thesis (although language may be more relaxed in places, such as the Acknowledgements section).
Consider rephrasing “in a nutshell” to briefly or in brief or in short. Rather than “hot topic” consider variations using phrases like “a subject undergoing intense study”, “receiving close review”, “of broad and current interest”, etc. Phrases like these add verbosity and weakness if overused but will raise no eyebrows.