OK Samatha here is my story. Lamba hai.

I did my PhD in the lab of an outstanding scientist - Prof. Umadas Maitra. He only worked with graduate students - all Bongs, almost exclusively from Biochemistry Dept. Of Calcutta University. He felt comfortable with these students. https://twitter.com/Samatha_Mathew/status/1310138842301702144

He always stayed away from the lime light but produced some of the best young scientists from the laboratory. You may search these names - Sankar Ghosh, Jayanta Chaudhary, Uttiya Basu, Samit Adhya etc.

He was interested in learning how protein synthesis is initiated in eukaryotes. Some may find it boring but he was excited to learn all that he could about this process. And he could transmit that enthusiasm to us. The method of choice was biochemistry.

We were good at purifying proteins from Rabbit reticulocytes and yeast S. cerevisae. I did not come up with my own problem. It was given to me. Problem - Translation initiation factors are highly conserved among eukaryotes, so much so that human genes could replace yeast genes.

However, eIF3 (eukaryotic initiation factor 3) was an exception. cerevisae eIF3 has only five subunits while vertebrate eIF3 had 10, suggesting evolutionarily acquired sophistication.

My job was to find out the role of the five extra subunits.

I could not do it in cerevisae using genetics as it does not have those. I couldn't approach using standard biochemistry because I wouldn't be able to separate the core subunits from the non-core ones.

I started from discovering the sequence of two such genes (remember this was pre-genome sequencing era).

Other labs reported sequence of the other genes.

I proposed to make a 10 subunit recombinant human eIF3 in insect expression system.

My mentor warned me against it.

However, I really wanted to do it.

My lab didn't have any cell culture system. I learned it in another lab. I worked like crazy for 2.5 years. I could make the 10 subunit recombinant protein. I was super proud. In those days it was considered very ambitious.

The recombinant protein "chromatographically" behaved just like d native counterpart but it was not active As the 10 subunit protein was not active, my plan of dissecting function of individual subunits by eliminating one at a time from the recombinant protein was a nonstarter

It has already been 4.5 years and I had nothing to show for

I was sad but didn't give up. One day, I suddenly discovered that the other popular yeast - S. pombe has all the 10 subunits. I was charged up again and proposed to knock out each of those genes in pombe.

This time my mentor promptly agreed (this is what experience does. One develops instincts). I requested a very good pombe geneticist to become my co-mentor, he agreed and I started.

It was fairly productive. It took me seven years to graduate.

My mentor knew that the recombinant protein approach wouldn't work but he let me do it nonetheless else I would have always thought he didn't let me pursue a brilliant idea

However, he demonstrated his confidence in me by letting me pursue the pombe genetics approach which was fairly alien to our lab.

Thus, your mentor's job is only to advice you, encourage you and support you - the rest is your battle to fight

All the best. Be ambitious.